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Using Bioinformatics to Define Possible Flexible Regions of Glutamate Dehydrogenases
Author(s) -
Hickman Tyler,
Aldina Rob,
Wacker Sarah,
Bell Ellis
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a54
Subject(s) - glutamate dehydrogenase , histidine , amino acid , biochemistry , conserved sequence , biology , glutamate receptor , allosteric regulation , eukaryote , dehydrogenase , chemistry , enzyme , peptide sequence , genome , receptor , gene
Higher Eukaryotic Glutamate Dehydrogenases show complex allosteric regulation. More primitive eukaryotes and prokaryotes have glutamate dehydrogenases that while calalyzing the same reaction show no, or very limited, regulatory properties. Data mining of a wide variety of glutamate dehydrogenase sequences and structures has led to insights into structure function relationships in this important enzyme and forms the basis of current experimental investigations. By examining and comparing the amino acid sequences of Glutamate Dehydrogenase in both higher eukaryotes and prokaryotes we find a number of completely conserved Gly‐Gly linkages which may be sites of local flexibility. However several additional Gly‐Gly linkages are conserved in prokaryotes and are absent in higher eukaryotes. Higher eukaryote sequences in addition to an approximately 50 amino acid insert that corresponds to the antenna region of the x ray structure show several conserved residues in the main domains of the structure that are not found in prokaryotic sequences including a histidine residue which we have mutated with complete loss of activity but apparent retention of structure. Interestingly Paramecium Glutamate Dehydrogenase has the insert but lacks the conserved histidine residue found in higher eukaryotes. Chain position analysis of the temperature factors for bovine and human glutamate dehydrogenase have been used to deternine whether there might be ligand‐induced changes in temperature facter. Several regions of the chain show significantly elevated temperature factors suggestion the existence of enhanced local flexibility. This work is supported by NSF Grant MCB 0448905 to EB