The J-protein family: modulating protein assembly, disassembly and translocation.
DnaJ is a molecular chaperone and the prototypical member of the J-protein family. J proteins are defined by the presence of a J domain that can regulate the activity of 70-kDa heat-shock proteins. Sequence analysis on the genome of Saccharomyces cerevisiae has revealed 22 proteins that establish four distinguishing structural features of the J domain: predicted helicity in segments I-IV, precisely placed interhelical contact residues, a lysine-rich surface on helix II and placement of the diagnostic sequence HPD between the predicted helices II and III. We suggest that this definition of the J-protein family could be used for other genome-wide studies. In addition, three J-like proteins were identified in yeast that contain regions closely resembling a J domain, but in which the HPD motif is non-conservatively replaced. We suggest that J-like proteins might function to regulate the activity of bona fide J proteins during protein translocation, assembly and disassembly.
Walsh
Peter
P
Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Melbourne 3010, Australia.
Bursać
Dejan
D
Law
Yin Chern
YC
Cyr
Douglas
D
Lithgow
Trevor
T
D000595:Amino Acid Sequence; D016681:Genome, Fungal; D006360:Heat-Shock Proteins / Q000145:classification / Q000502:physiology*; D018832:Molecular Chaperones / Q000145:classification / Q000502:physiology*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000145:classification / Q000502:physiology*; D016415:Sequence Alignment
D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins