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Crystal Volume (crystal + volume)
Selected AbstractsEntrapment of a Hexamer of Nitrobenzene Molecules between the Layers of (4,4)-Coordination Networks Containing Intra-,-Sheet Hydrogen BondsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2006Madhushree Sarkar Abstract Two exo -bidentate pyridyl ligands containing diamides as spacers were shown to form non-interpenetrated 2D-coordination networks of (4,4)-geometry upon treatment with Cu(NO3)2 and NaSCN. The crystal structures reveal that both structures contain intralayer ,-sheet hydrogen bonds. In one of these structures nitrobenzene occupies 60,% of the crystal volume included between the coordination networks. The nitrobenzene molecules form a layer which has the hexameric C,H···O hydrogen bonded aggregate as a basic building block. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] High-resolution neutron protein crystallography with radically small crystal volumes: application of perdeuteration to human aldose reductaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2005I. Hazemann Neutron diffraction data have been collected to 2.2,Å resolution from a small (0.15,mm3) crystal of perdeuterated human aldose reductase (h-AR; MW = 36,kDa) in order to help to determine the protonation state of the enzyme. h-AR belongs to the aldo,keto reductase family and is implicated in diabetic complications. Its ternary complexes (h-AR,coenzyme NADPH,selected inhibitor) provide a good model to study both the enzymatic mechanism and inhibition. Here, the successful production of fully deuterated human aldose reductase [h-AR(D)], subsequent crystallization of the ternary complex h-AR(D),NADPH,IDD594 and neutron Laue data collection at the LADI instrument at ILL using a crystal volume of just 0.15,mm3 are reported. Neutron data were recorded to 2,Å resolution, with subsequent data analysis using data to 2.2,Å. This is the first fully deuterated enzyme of this size (36,kDa) to be solved by neutron diffraction and represents a milestone in the field, as the crystal volume is at least one order of magnitude smaller than those usually required for other high-resolution neutron structures determined to date. This illustrates the significant increase in the signal-to-noise ratio of data collected from perdeuterated crystals and demonstrates that good-quality neutron data can now be collected from more typical protein crystal volumes. Indeed, the signal-to-noise ratio is then dominated by other sources of instrument background, the nature of which is under investigation. This is important for the design of future instruments, which should take maximum advantage of the reduction in the intrinsic diffraction pattern background from fully deuterated samples. [source] Crystallization and preliminary X-ray crystallographic study of leucyl-tRNA synthetase from the archaeon Pyrococcus horikoshiiACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2004Ryuya Fukunaga The leucyl-tRNA synthetase (LeuRS) from the archaeon Pyrococcus horikoshii was overexpressed in a C-terminally truncated form in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. The crystals belong to the rhombohedral space group R3, with unit-cell parameters a = b = 186.20, c = 91.43,Å, , = , = 90, , = 120°. The asymmetric unit contains one molecule of LeuRS, with a corresponding crystal volume per protein weight of 3.2,Å3,Da,1 and a solvent content of 60.7%. A data set diffracting to 2.2,Å resolution was collected from a single crystal at 100,K. Selenomethionine-substituted protein crystals were prepared in order to solve the structure by the SAD phasing method. [source] Crystallization and preliminary X-ray crystallographic analysis of the RecR protein from Deinococcus radiodurans, a member of the RecFOR DNA-repair pathwayACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2004Byung Il Lee The RecR protein plays a key role in the RecFOR pathway of recombination, which is necessary for the repair of ssDNA gaps. RecR from Deinococcus radiodurans has been overexpressed in Escherichia coli and crystallized at 297,K using polyethylene glycol 1000 as a precipitant. X-ray diffraction data to 2.90,Å resolution have been collected at 100,K using Cu,K, X-rays from a mercury-soaked crystal. The crystal belongs to space group C2221, with unit-cell parameters a = 106.96, b = 122.25, c = 156.01,Å. The asymmetric unit contains four monomers of RecR, with a crystal volume per protein weight (VM) of 2.57,Å3,Da,1 and a solvent content of 51.0%. [source] Crystallization and preliminary X-ray data investigation of the bacterial enterocin A immunity protein at 1.65,Å resolutionACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2003Bjørn Dalhus Crystals of the bacterial enterocin A immunity protein have been prepared by the hanging-drop vapour-diffusion technique at 293,K. The crystals diffract to better than 1.7,Å resolution and X-ray diffraction data to 1.65,Å have been collected at 110,K using synchrotron radiation. The enterocin A immunity protein crystals belong to the monoclinic crystal system, with unit-cell parameters a = 116.32, b = 42.35, c = 66.17,Å, , = 111.3°. The symmetry and systematic absences in the diffraction pattern are consistent with space group C2. The presence of two molecules in the asymmetric unit with a molecular weight of ,12.2,kDa gives a crystal volume per protein mass (VM) of ,3.1,Å3,Da,1 and a solvent content of ,60% by volume. [source] Crystallization and preliminary crystallographic analysis of extracellular fragment X3 of YWK-II/APPH: a human sperm membrane protein related to the Alzheimer ,A4-amyloid precursor proteinACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2003Wangjun Hu Crystals of extracellular fragment X3 of a human sperm membrane protein YWK-II/APPH have been grown at 291,K using 8% PEG 4000 as precipitant by the vapour-diffusion method. The diffraction pattern of the crystal extends to 2.9,Å resolution at 100,K using Cu,K, radiation in-house. The crystals belong to space group P21, with unit-cell parameters a = 46.0, b = 43.7, c = 90.2,Å, , = , = 90.0, , = 106.6°. Furthermore, a selenomethionine (SeMet) derivative of the protein was overexpressed in the same expression system and was purified in a reducing environment. The derivative crystals were obtained under similar conditions. Subsequently, a single-wavelength data set was collected to 2.38,Å resolution from the derivative crystal at ESRF. The crystals belong to space group P21, with unit-cell parameters a = 46.2, b = 44.0, c = 88.3,Å, , = , = 90.0, , = 103.6°. The presence of one molecule per asymmetric unit gives a crystal volume per protein mass (VM) of 2.8,Å3,Da,1 and a solvent content of 56.4% by volume. [source] Crystallization and preliminary crystallographic analysis of a partial extracellular fragment of a sperm membrane protein YWK-II/APPH related to the Alzheimer ,A4-amyloid precursor proteinACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2003Maojun Yang Crystals of a partial extracellular fragment of a human sperm membrane protein YWK-II/APPH have been grown at 291,K using PEG 4000 as precipitant. The diffraction pattern of the crystal extends to 2.8,Å resolution at 100,K using Cu,K, radiation. The crystals belong to space group P212121, with unit-cell parameters a = 46.009, b = 67.387, c = 149.241,Å, , = , = , = 90°. The presence of two molecules per asymmetric unit gives a crystal volume per protein mass (VM) of 3.51,Å3,Da,1 and a solvent content of 64.6% by volume. A full set of X-ray diffraction data were collected to 2.8,Å resolution from the native crystal. [source] Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase from Pseudomonas aeruginosaACTA CRYSTALLOGRAPHICA SECTION D, Issue 10-2 2002Hyung-Wook Kim Peptide deformylase (PDF) from the pathogenic bacterium Pseudomonas aeruginosa has been overexpressed in Escherichia coli and crystallized in the presence of its inhibitor actinonin at 297,K using polyethylene glycol (PEG) 4000 as a precipitant. The diffraction limit and the spot shape of the crystals could be slightly improved by the crystal annealing/dehydration procedure. X-ray diffraction data to 1.85,Å have been collected using synchrotron radiation. The crystal belongs to the orthorhombic space group P212121, with unit-cell parameters a = 68.75, b = 74.46, c = 77.18,Å. The asymmetric unit contains two subunits of peptide deformylase, with a corresponding crystal volume per protein mass (VM) of 2.45,Å3,Da,1 and a solvent content of 49.8%. [source] Crystallization and preliminary X-ray diffraction analysis of glutamate dehydrogenase from an aerobic hyperthermophilic archaeon, Aeropyrum pernix K1ACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2002Mohammad W. Bhuiya Glutamate dehydrogenase from an aerobic hyperthermophilic archaeon, Aeropyrum pernix K1, was crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol (PEG) 400 as the precipitant. The crystals belong to the hexagonal space group P63, with unit-cell parameters a = b = 98.9, c = 394.8,Å, , = , = 90, , = 120°. The asymmetric unit contained one hexamer of the enzyme, giving a crystal volume per enzyme mass (VM) of 1.98,Å3,Da,1 and a solvent content of 37.3%. The X-ray diffraction data were collected to a resolution of 3.0,Å at the BL6B beamline in the Photon Factory with an overall Rsym of 13.8% and a completeness of 87.1%. [source] Crystallization and preliminary X-ray crystallographic analysis of p24, a component of the potato nuclear factor PBF-2ACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2002Darrell Desveaux The Solanum tuberosum (potato) nuclear factor PBF-2 is implicated in pathogen-induced expression of the pathogenesis-related gene PR-10a. Crystals of the DNA-binding component of PBF-2, p24, have been obtained at 277,K in 20,mM Tris,HCl pH 8.0. Recombinant protein with a His tag at its C-terminus was overexpressed in Escherichia coli in the presence and absence of selenomethionine and was purified using a combination of HiTrap affinity columns and gel-filtration chromatography. Crystals suitable for structural analysis were obtained for both native and selenomethionine-labelled proteins and yielded diffraction data at 100,K that were processed to 2.3 and 2.8,Å resolution, respectively. The p24 protein crystals belong to space group P212121, with unit-cell parameters a = 69.4,(69.1), b = 89.4,(90.5), c = 144.1,(144.3),Å. The asymmetric unit contains four protomers, giving a crystal volume per protein mass (VM) of 2.23,Å3,Da,1 and a solvent content of 45% by volume. [source] Crystallization and preliminary X-ray crystallographic analysis of deoxyuridine triphosphate nucleotidohydrolase from Saccharomyces cerevisiaeACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2001Byung Woo Han Deoxyuridine triphosphate nucleotidohydrolase (dUTPase) from Saccharomyces cerevisiae is essential for cell viability. It has been overexpressed in Escherichia coli and has been crystallized at 296,K using polyethylene glycol (PEG) 1500 as a precipitant. The crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 59.48, b = 138.54, c = 157.91,Å, , = , = , = 90°. Two molecules of trimeric dUTPase from S. cerevisiae are present in the asymmetric unit, giving a crystal volume per protein mass (VM) of 3.36,Å3,Da,1 and a solvent content of 63%. The diffraction limit of the crystals could be significantly extended by the crystal-annealing procedure. A set of native data extending to 2.7,Å resolution has been collected at 100,K using synchrotron X-rays. [source] Overexpression, crystallization and preliminary X-ray crystallographic analysis of Pseudomonas aeruginosa MnmE, a GTPase involved in tRNA modificationACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2010Hyung Ho Lee MnmE, an evolutionarily conserved GTPase, is involved in modification of the uridine base (U34) at the wobble position of certain tRNAs. Previous crystal structures of MnmE suggest that it is a dimer with considerable conformational flexibility. To facilitate structural comparisons among MnmE proteins, structural analysis of MnmE from Pseudomonas aeruginosa encoded by the PA5567 gene was initiated. It was overexpressed in Escherichia coli and crystallized at 297,K using a reservoir solution consisting of 100,mM sodium ADA pH 6.5, 12%(w/v) polyethylene glycol 4000, 100,mM lithium sulfate, 2%(v/v) 2-propanol and 2.5,mM dithiothreitol. X-ray diffraction data were collected to 2.69,Å resolution. The crystals belonged to the orthorhombic space group C2221, with unit-cell parameters a = 96.74, b = 204.66, c = 120.90,Å. Two monomers were present in the asymmetric unit, resulting in a crystal volume per protein mass (VM) of 2.99,Å3,Da,1 and a solvent content of 58.8%. [source] Crystallization and preliminary crystallographic studies of the butyrolactone autoregulator receptor protein (BarA) from Streptomyces virginiaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2010Young-Ho Yoon The Streptomyces butyrolactone autoregulator receptor protein (BarA) is a DNA-binding protein that regulates the biosynthesis of the antibiotic virginiamycin. In this study, BarA from S. virginiae was overexpressed in Escherichia coli, purified and crystallized. Crystals of purified protein have been grown that diffracted to beyond 3.0,Å resolution at 100,K using synchrotron radiation. The protein crystals belonged to the hexagonal space group P6522, with unit-cell parameters a = b = 128.0, c = 286.2,Å. With four molecules per asymmetric unit, the crystal volume per unit protein mass (VM) was 3.2,Å3,Da,1 and the solvent content was 62%. [source] Crystallization and preliminary X-ray diffraction analysis of the complex of a human anti-ephrin type-A receptor 2 antibody fragment and its cognate antigenACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2010Vaheh Oganesyan The recombinant N-terminal domain of human ephrin type-A receptor 2 (rEphA2) has been crystallized in complex with the recombinantly produced Fab fragment of a fully human antibody (1C1; IgG1/,). These are the first reported crystals of an ephrin receptor bound to an antibody. The orthorhombic crystals belonged to space group C2221 (the 00l reflections obey the l = 2n rule), with unit-cell parameters a = 78.93, b = 120.79, c = 286.20,Å. The diffraction of the crystals extended to 2.0,Å resolution. However, only data to 2.55,Å resolution were considered to be useful owing to spot overlap caused by the long unit-cell parameter. The asymmetric unit is most likely to contain two 1C1 Fab,rEphA2 complexes. This corresponds to a crystal volume per protein weight (VM) of 2.4,Å3,Da,1 and a solvent content of 49.5%. The three-dimensional structure of this complex will shed light on the molecular basis of 1C1 specificity. This will also contribute to a better understanding of the mechanism of action of this antibody, the current evaluation of which as an antibody,drug conjugate in cancer therapy makes it a particularly interesting case study. [source] Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of 2-keto-3-deoxy-6-phosphogluconate aldolase from Zymomonas mobilis ZM4ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2010Ho-Chang Ryu Zymomonas mobilis ZM4 is an organism optimized for ethanol production which uses the Entner,Doudoroff (ED) pathway for the breakdown of glucose. The key enzyme in this process is 2-keto-3-deoxy-6-phosphogluconate (KDPG) aldolase, which produces glyceraldehyde 3-phosphate and pyruvate. In order to provide a molecular background for the KDPG aldolase from this ethanologenic organism (zmKDPG aldolase), the ZMO0997 gene of Z. mobilis ZM4 coding for zmKDPG aldolase was cloned and expressed and the purified protein was crystallized from 25%(w/v) polyethylene glycol 3350 and 0.1,M bis-tris pH 5.5. Diffraction data were collected to 1.8,Å resolution using synchrotron radiation. The crystal belonged to the orthorhombic space group P212121, with unit-cell parameters a = 63.7, b = 83.0, c = 117.2,Å. A trimeric zmKDPG aldolase molecule was present in the asymmetric unit, resulting in a crystal volume per unit protein weight of 2.40,Å3,Da,1 and a solvent content of 48%. [source] Crystallization and preliminary X-ray analysis of the diadenosine 5,,5,,,- P1,P4 -tetraphosphate phosphorylase from Mycobacterium tuberculosis H37RvACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Shigetarou Mori A novel diadenosine 5,,5,,,- P1,P4 -tetraphosphate (Ap4A) phosphorylase (Rv2613c) from Mycobacterium tuberculosis H37Rv has been crystallized by the sitting-drop vapour-diffusion method. The crystal belonged to space group C2, with unit-cell parameters a = 101.5, b = 63.6, c = 79.1,Å, , = 110.9°. The diffraction of the crystals extended to 1.9,Å resolution. The asymmetric unit is expected to contain two molecules of Rv2613c, with a corresponding crystal volume per protein weight (VM) of 2.41,Å3,Da,1 and a solvent content of 49.1%. This is the first report of a crystal of Ap4A phosphorylase. [source] Expression, crystallization and preliminary X-ray diffraction analysis of a modification subunit of a putative type I restriction enzyme from Vibrio vulnificus YJ016ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 12 2009Hyun-Ju Lee Modification (HsdM) and specificity (HsdS) subunits are constituents of an active methyltransferase (MTase) of multifunctional type I restriction enzymes. To provide a molecular background on HsdM, a putative hsdM gene from Vibrio vulnificus YJ016 (HsdM_Vv) was cloned and the expressed protein was purified and crystallized from 22%(w/v) polyethylene glycol 8000, 0.02,M imidazole pH 7.5 and 5,mM,-mercaptoethanol. Diffraction data were collected to 1.86,Å resolution using synchrotron radiation. The crystal belonged to the tetragonal space group P41212 or P43212, with unit-cell parameters a = b = 78.9, c = 165.8,Å. With one molecule in the asymmetric unit, the crystal volume per unit protein weight was 2.12,Å3,Da,1, with a solvent content of 42%. [source] Engineering an improved crystal contact across a solvent-mediated interface of human fibroblast growth factor 1ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2009Akshaya K. Meher Large-volume protein crystals are a prerequisite for neutron diffraction studies and their production represents a bottleneck in obtaining neutron structures. Many protein crystals that permit the collection of high-resolution X-ray diffraction data are inappropriate for neutron diffraction owing to a plate-type morphology that limits the crystal volume. Human fibroblast growth factor 1 crystallizes in a plate morphology that yields atomic resolution X-ray diffraction data but has insufficient volume for neutron diffraction. The thin physical dimension has been identified as corresponding to the b cell edge and the X-ray structure identified a solvent-mediated crystal contact adjacent to position Glu81 that was hypothesized to limit efficient crystal growth in this dimension. In this report, a series of mutations at this crystal contact designed to both reduce side-chain entropy and replace the solvent-mediated interface with direct side-chain contacts are reported. The results suggest that improved crystal growth is achieved upon the introduction of direct crystal contacts, while little improvement is observed with side-chain entropy-reducing mutations alone. [source] Crystallization of mitochondrial rhodoquinol-fumarate reductase from the parasitic nematode Ascaris suum with the specific inhibitor flutolanilACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009Arihiro Osanai In adult Ascaris suum (roundworm) mitochondrial membrane-bound complex II acts as a rhodoquinol-fumarate reductase, which is the reverse reaction to that of mammalian complex II (succinate-ubiquinone reductase). The adult A. suum rhodoquinol-fumarate reductase was crystallized in the presence of octaethyleneglycol monododecyl ether and n -dodecyl-,- d -maltopyranoside in a 3:2 weight ratio. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 123.75, b = 129.08, c = 221.12,Å, and diffracted to 2.8,Å resolution using synchrotron radiation. The presence of two molecules in the asymmetric unit (120,kDa × 2) gives a crystal volume per protein mass (VM) of 3.6,Å3,Da,1. [source] Crystallization and preliminary X-ray diffraction analysis of the complex between a human anti-interferon antibody fragment and human interferon ,-2AACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2009Vaheh Oganesyan Recombinant human interferon ,-2A (rhIFN-,-2A) has been crystallized in complex with the recombinantly produced Fab fragment of a therapeutic monoclonal antibody (MEDI545; IgG1/,) which targets several human interferon , subtypes. This constitutes the first reported crystals of a human type I interferon bound to an antibody. The orthorhombic crystals belonged to either space group I222 or I212121, with unit-cell parameters a = 134.82, b = 153.26, c = 163.49,Å. The diffraction of the crystals extended to 3.0,Å resolution. The asymmetric unit contained two Fab,rhIFN-,-2A complexes. This corresponded to a crystal volume per protein weight (VM) of 3.02,Å3,Da,1 and a solvent content of 59.3%. The corresponding three-dimensional structure is expected to shed light on the mechanism of action of MEDI545 and the molecular basis of its specificity. [source] Expression, purification and crystallization of Trypanosoma cruzi dihydroorotate dehydrogenase complexed with orotateACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2005Daniel Ken Inaoka Dihydroorotate dehydrogenase (DHOD) catalyzes the oxidation of dihydroorotate to orotate, the fourth step and the only redox reaction in the de novo biosynthesis of pyrimidine. DHOD from Trypanosoma cruzi (TcDHOD) has been expressed as a recombinant protein in Escherichia coli and purified to homogeneity. Crystals of the TcDHOD,orotate complex were grown at 277,K by the sitting-drop vapour-diffusion technique using polyethylene glycol 3350 as a precipitant. The crystals diffract to better than 1.8,Å resolution using synchrotron radiation (, = 0.900,Å). X-ray diffraction data were collected at 100,K and processed to 1.9,Å resolution with 98.2% completeness and an overall Rmerge of 7.8%. The TcDHOD crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 67.87, b = 71.89, c = 123.27,Å. The presence of two molecules in the asymmetric unit (2 × 34,kDa) gives a crystal volume per protein weight (VM) of 2.2,Å3,Da,1 and a solvent content of 44%. [source] Crystallization and X-ray analysis of 2-deoxy- scyllo -inosose synthase, the key enzyme in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibioticsACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2005Eriko Nango A recombinant 2-deoxy- scyllo -inosose synthase from Bacillus circulans has been crystallized at 277,K using PEG 4000 as precipitant. The diffraction pattern of the crystal extends to 2.30,Å resolution at 100,K using synchrotron radiation at the Photon Factory. The crystals are monoclinic and belong to space group P21, with unit-cell parameters a = 80.5, b = 70.4, c = 83.0,Å, , = 117.8°. The presence of two molecules per asymmetric unit gives a crystal volume per protein weight (VM) of 2.89,Å3,Da,1 and a solvent constant of 57.4% by volume. [source] High-resolution neutron protein crystallography with radically small crystal volumes: application of perdeuteration to human aldose reductaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2005I. Hazemann Neutron diffraction data have been collected to 2.2,Å resolution from a small (0.15,mm3) crystal of perdeuterated human aldose reductase (h-AR; MW = 36,kDa) in order to help to determine the protonation state of the enzyme. h-AR belongs to the aldo,keto reductase family and is implicated in diabetic complications. Its ternary complexes (h-AR,coenzyme NADPH,selected inhibitor) provide a good model to study both the enzymatic mechanism and inhibition. Here, the successful production of fully deuterated human aldose reductase [h-AR(D)], subsequent crystallization of the ternary complex h-AR(D),NADPH,IDD594 and neutron Laue data collection at the LADI instrument at ILL using a crystal volume of just 0.15,mm3 are reported. Neutron data were recorded to 2,Å resolution, with subsequent data analysis using data to 2.2,Å. This is the first fully deuterated enzyme of this size (36,kDa) to be solved by neutron diffraction and represents a milestone in the field, as the crystal volume is at least one order of magnitude smaller than those usually required for other high-resolution neutron structures determined to date. This illustrates the significant increase in the signal-to-noise ratio of data collected from perdeuterated crystals and demonstrates that good-quality neutron data can now be collected from more typical protein crystal volumes. Indeed, the signal-to-noise ratio is then dominated by other sources of instrument background, the nature of which is under investigation. This is important for the design of future instruments, which should take maximum advantage of the reduction in the intrinsic diffraction pattern background from fully deuterated samples. [source] | ||||||||||