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Moraxella Sp (moraxella + sp)

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Chemistry100%

Selected Abstracts

Structures of the apo and holo forms of formate dehydrogenase from the bacterium Moraxella sp.

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2009
C-1: towards understanding the mechanism of the closure of the interdomain cleft
NAD+ -dependent formate dehydrogenase (FDH) catalyzes the oxidation of formate ion to carbon dioxide coupled with the reduction of NAD+ to NADH. The crystal structures of the apo and holo forms of FDH from the methylotrophic bacterium Moraxella sp. C-1 (MorFDH) are reported at 1.96 and 1.95,Å resolution, respectively. MorFDH is similar to the previously studied FDH from the bacterium Pseudomonas sp. 101 in overall structure, cofactor-binding mode and active-site architecture, but differs in that the eight-residue-longer C-terminal fragment is visible in the electron-density maps of MorFDH. MorFDH also differs in the organization of the dimer interface. The holo MorFDH structure supports the earlier hypothesis that the catalytic residue His332 can form a hydrogen bond to both the substrate and the transition state. Apo MorFDH has a closed conformation of the interdomain cleft, which is unique for an apo form of an NAD+ -dependent dehydrogenase. A comparison of the structures of bacterial FDH in open and closed conformations allows the differentiation of the conformational changes associated with cofactor binding and domain motion and provides insights into the mechanism of the closure of the interdomain cleft in FDH. The C-terminal residues 374,399 and the substrate (formate ion) or inhibitor (azide ion) binding are shown to play an essential role in the transition from the open to the closed conformation. [source]

Crystallization and preliminary X-ray diffraction studies of an alcohol dehydrogenase from the Antarctic psychrophile Moraxella sp.

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2005
TAE12
An NAD+ -dependent psychrophilic alcohol dehydrogenase (ADH) from the Antarctic psychrophile Moraxella sp. TAE123 has been purified to homogeneity. The enzyme consists of four identical subunits, each containing two Zn ions. Protein crystals suitable for X-ray diffraction were obtained under optimized salting-out crystallization conditions using ammonium sulfate as a precipitating agent. The crystals are hexagonal bipyramids and belong to space group P3121 or P3221, with unit-cell parameters a = 136.4, c = 210.7,Å. They contain one protein homotetramer in the asymmetric unit. Diffraction data were collected to 2.2,Å under cryogenic conditions using synchrotron radiation. [source]