Autonomous folding of the excised coenzyme-binding domain of D-glyceraldehyde 3-phosphate dehydrogenase from Thermotoga maritima.
An important question in protein folding is whether compact substructures or domains are autonomous units of folding and assembly. The protomer of the tetrameric D-glyceraldehyde-3-phosphate dehydrogenase from the hyperthermophilic bacterium Thermotoga maritima has a complex coenzyme-binding domain, in which residues 1-146 form a compact substructure with the last 31 residues (313-333). Here it is shown that the gene of a single-chain protein can be expressed in Escherichia coli after deleting the 163 codons corresponding to the interspersed catalytic domain (150-312). The purified gene product is a soluble, monomeric protein that binds both NAD+ and NADH strongly and possesses the same unfolding transition induced by guanidinium chloride as the native tetramer. The autonomous folding of the coenzyme-binding domain has interesting implications for the folding, assembly, function, and evolution of the native enzyme.
Institut für Biophysik und Physikalische Biochemie, Universität Regensburg, Germany.
M
M
Jecht
A
A
Tomschy
K
K
Kirschner
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R
Jaenicke
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003067:Coenzymes / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004795:Enzyme Stability; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006089:Gram-Negative Anaerobic Bacteria / Q000201:enzymology* / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D009243:NAD / Q000378:metabolism; D017510:Protein Folding; D017384:Sequence Deletion; D013053:Spectrophotometry
D003067:Coenzymes; D004269:DNA, Bacterial; D009243:NAD; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases