Structural resemblance between the families of bacterial signal-transduction proteins and of G proteins revealed by graph theoretical techniques.
The first application of a novel technique for the identification of common folding motifs in proteins is presented. Using techniques derived from graph theory, developed in order to compare secondary structure motifs in proteins, we have established that there is a striking resemblance in the tertiary fold of the Salmonella typhimurium Che Y chemotaxis protein and that of the GDP-binding domain of Escherichia coli elongation factor Tu (EF Tu). These two protein structures are representatives of two major macromolecular classes: CheY is a signal-transduction protein with sequence homologies to a wide range of bacterial proteins involved in regulation of chemotaxis, membrane synthesis and sporulation; whilst EF Tu is one of a family of guanosine-nucleotide-binding proteins which include the ras oncogene proteins and signal-transducing G proteins. The similarity we have found extends far beyond the previously recognized resemblances of each protein's fold to that of a generic nucleotide-binding domain. The lack of significant sequence homology between the two classes of proteins may mean that the common fold of the two proteins constitutes a particularly stable folding motif. However, an alternative possibility is that the strong three-dimensional structural resemblance may be indicative of a remote shared common ancestry between the bacterial signal-transduction proteins and the GDP-binding proteins.
Artymiuk
P J
PJ
Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, Sheffield, UK.
Rice
D W
DW
Mitchell
E M
EM
Willett
P
P
D000465:Algorithms; D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D002630:Chemotactic Factors / Q000737:chemistry*; D004926:Escherichia coli / Q000648:ultrastructure; D029968:Escherichia coli Proteins; D019204:GTP-Binding Proteins / Q000737:chemistry*; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000737:chemistry*; D000072236:Methyl-Accepting Chemotaxis Proteins; D008969:Molecular Sequence Data; D010444:Peptide Elongation Factor Tu / Q000737:chemistry; D011487:Protein Conformation; D012486:Salmonella typhimurium / Q000648:ultrastructure*; D012689:Sequence Homology, Nucleic Acid; D015398:Signal Transduction; D012984:Software
D001426:Bacterial Proteins; D002630:Chemotactic Factors; D029968:Escherichia coli Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C000607606:cheY protein, E coli; D019204:GTP-Binding Proteins; D010444:Peptide Elongation Factor Tu