Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
1997-10-22
pubmed:abstractText
The solution of the three-dimensional structure of Bacillus sphaericus leucine dehydrogenase has enabled us to undertake a homology-based modeling exercise on the sequence differences between the families of leucine (LeuDH) and valine (ValDH) dehydrogenases. This analysis indicates that the secondary structure elements in the core of the two domains of a single subunit of these enzymes are conserved, as are residues directly implicated in the recognition of the nucleotide cofactor and in catalysis. Comparison of the sequences indicates that the residues in the pocket accommodating the side chain of the amino acid substrate are conserved between these two enzymes, suggesting that the small differences in specificity arise from minor changes in molecular structure, possibly associated with shifts of the main chain rather than mutation of residues in the pocket itself. While B. sphaericus LeuDH is an octamer, both Streptomyces cinnamonensis and Streptomyces coelicolor ValDHs are dimers. The differences in quaternary structure can be understood in terms of the deletion in the latter of a C-terminal loop, which forms important interactions around the four-fold axis in LeuDH.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
272
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25105-11
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9312120-Amino Acid Oxidoreductases, pubmed-meshheading:9312120-Amino Acid Sequence, pubmed-meshheading:9312120-Bacillus, pubmed-meshheading:9312120-Catalysis, pubmed-meshheading:9312120-Crystallography, X-Ray, pubmed-meshheading:9312120-Dimerization, pubmed-meshheading:9312120-Leucine Dehydrogenase, pubmed-meshheading:9312120-Macromolecular Substances, pubmed-meshheading:9312120-Models, Structural, pubmed-meshheading:9312120-Molecular Sequence Data, pubmed-meshheading:9312120-Point Mutation, pubmed-meshheading:9312120-Protein Conformation, pubmed-meshheading:9312120-Protein Structure, Secondary, pubmed-meshheading:9312120-Protein Structure, Tertiary, pubmed-meshheading:9312120-Sequence Alignment, pubmed-meshheading:9312120-Sequence Homology, Amino Acid, pubmed-meshheading:9312120-Streptomyces, pubmed-meshheading:9312120-Substrate Specificity
pubmed:year
1997
pubmed:articleTitle
Analysis of the quaternary structure, substrate specificity, and catalytic mechanism of valine dehydrogenase.
pubmed:affiliation
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, United Kingdom.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't