Genetic analysis of bacteriophage-encoded cochaperonins.
Early genetic studies identified the Escherichia coli groES and groEL genes because mutations in them blocked the growth of bacteriophages lambda and T4. Subsequent genetic and biochemical analyses have shown that GroES and GroEL constitute a chaperonin machine, absolutely essential for E. coli growth, because it is needed for the correct folding of many of its proteins. In spite of very little sequence identity to GroES, the bacteriophage T4-encoded Gp31 protein and the bacteriophage RB49-encoded CocO protein are bona fide GroEL cochaperonins, even capable of substituting for GroES in E. coli growth. A major functional distinction is that only Gp31 and CocO can assist GroEL in the correct folding of Gp23, the major bacteriophage capsid protein. Conserved structural features between CocO and Gp31, which are absent from GroES, highlight their potential importance in specific cochaperonin function.
Ang
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D
Département de Biochimie Médicale, Centre Médical Universitaire, 1 rue Michel Servet, Genève 4, CH-1211 Switzerland. deborah.ang@medecine.unige.ch
Keppel
F
F
Klein
G
G
Richardson
A
A
Georgopoulos
C
C
D001426:Bacterial Proteins / Q000235:genetics; D017122:Bacteriophage T4 / Q000235:genetics*; D018833:Chaperonins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C028715:GroE protein, E coli; D006360:Heat-Shock Proteins; D014764:Viral Proteins; C063473:gene 31 protein, Enterobacteria phage T4; D018833:Chaperonins