			Home About us Contact

Domain B (domain + b)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Expression of the Extra Domain B of Fibronectin, a Marker of Angiogenesis, in Head and Neck Tumors,

THE LARYNGOSCOPE, Issue 7 2003
Manfred T. Birchler MD
Abstract Objectives/Hypothesis The extra domain B (ED-B) of fibronectin, a naturally occurring marker of tissue remodeling and angiogenesis, is expressed in the majority of aggressive solid human tumors, whereas it is not detectable in normal vessels and tissues. Study Design In view of the diagnostic and therapeutic clinical applications of the L19 antibody, which is specific for the ED-B domain of fibronectin, a prospective immunohistochemical analysis of different head and neck tumors was performed. Methods In all, 82 head and neck tissue biopsy specimens were immunohistochemically analyzed using the L19 antibody. They consisted of 53 different malignant tumors, 8 benign tumors, 10 nontumoral lesions, and 11 normal control tissues. Results A strong positive staining with the L19 antibody could be observed in 87% of the investigated malignant tumors, in only 38% of the benign tumors, and in 20% of the nontumoral lesions (P <.0001). The extra domain B was completely absent in the normal control tissue samples. Conclusions The results show that ED-B is abundantly expressed around the neovasculature and in the stroma of the majority of malignant tumors of the head and neck but is undetectable in normal tissues. The ED-B domain of fibronectin is a good-quality tumor-stroma,associated antigen that warrants clinical trials with antibody-based pharmaceuticals, including immunoscintigraphic investigations and radioimmunoguided surgery with the radiolabeled L19 antibody. [source]

Identification and molecular analysis of candidate genes homologous to HcrVf genes for scab resistance in apple

PLANT BREEDING, Issue 1 2009
A. Boudichevskaia
Abstract The genetic locus for resistance to apple scab most frequently used in apple breeding is Vf, derived from Malus floribunda 821. For the Vf locus a cluster of four resistance gene paralogs (called as HcrVf genes) encoding receptor-like proteins (RLP) with similarity to the tomato Cf resistance genes is known. Based on published sequences for HcrVf1 and HcrVf2 PCR primers were designed from the domain B and the variable leucine-rich repeat (LRR) C1 subdomain. PCR products with high amino acid identity (85,100%) to HcrVf1 and HcrVf2 were obtained not only from M. floribunda 821 and Vf cultivars but also from other apple scab resistance sources, such as ,Russian Seedling' R12740-7A (Vr resistance) or ,Antonovka polutorafuntovaya' (VA resistance). A series of 13 HcrVf candidate genes have been partly cloned from the PCR fragments spanning N-terminal LRRs 20,30. A considerable number of amino acid exchanges within the solvent-exposed xxLxLxx structural motives were detected among the homologous sequences. Expression analyses and mapping focused on a selected Vf- homologous candidate gene (called Vf2ARD) identified in resistant Malus genotypes known for carrying other scab resistance genes than Vf. RT-PCR experiments showed that Vf2ARD is expressed under pathogen-free conditions. The results of a quantitative PCR-based transcription profiling suggest that this gene is scab-inducible in some resistant cultivars. Vf2ARD has been mapped on linkage group LG 1. It is separated from the Vf gene cluster with a genetic distance of about 2 cM and might be a member of a second Vf - like locus on apple linkage group LG 1. [source]

A charged residue at the subunit interface of PCNA promotes trimer formation by destabilizing alternate subunit interactions

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 6 2009
Bret D. Freudenthal
Eukaryotic proliferating cell nuclear antigen (PCNA) is an essential replication accessory factor that interacts with a variety of proteins involved in DNA replication and repair. Each monomer of PCNA has an N-terminal domain A and a C-terminal domain B. In the structure of the wild-type PCNA protein, domain A of one monomer interacts with domain B of a neighboring monomer to form a ring-shaped trimer. Glu113 is a conserved residue at the subunit interface in domain A. Two distinct X-ray crystal structures have been determined of a mutant form of PCNA with a substitution at this position (E113G) that has previously been studied because of its effect on translesion synthesis. The first structure was the expected ring-shaped trimer. The second structure was an unanticipated nontrimeric form of the protein. In this nontrimeric form, domain A of one PCNA monomer interacts with domain A of a neighboring monomer, while domain B of this monomer interacts with domain B of a different neighboring monomer. The B,B interface is stabilized by an antiparallel ,-sheet and appears to be structurally similar to the A,B interface observed in the trimeric form of PCNA. The A,A interface, in contrast, is primarily stabilized by hydrophobic interactions. Because the E113G substitution is located on this hydrophobic surface, the A,A interface should be less favorable in the case of the wild-type protein. This suggests that the side chain of Glu113 promotes trimer formation by destabilizing these possible alternate subunit interactions. [source]

Structure of Bacillus amyloliquefaciens,-amylase at high resolution: implications for thermal stability

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2010
Jahan Alikhajeh
The crystal structure of Bacillus amyloliquefaciens,-amylase (BAA) at 1.4,Å resolution revealed ambiguities in the thermal adaptation of homologous proteins in this family. The final model of BAA is composed of two molecules in a back-to-back orientation, which is likely to be a consequence of crystal packing. Despite a high degree of identity, comparison of the structure of BAA with those of other liquefying-type ,-amylases indicated moderate discrepancies at the secondary-structural level. Moreover, a domain-displacement survey using anisotropic B -factor and domain-motion analyses implied a significant contribution of domain B to the total flexibility of BAA, while visual inspection of the structure superimposed with that of B. licheniformis,-amylase (BLA) indicated higher flexibility of the latter in the central domain A. Therefore, it is suggested that domain B may play an important role in liquefying ,-amylases, as its rigidity offers a substantial improvement in thermostability in BLA compared with BAA. [source]