lamoran@gpu.utcs.utoronto.ca (L.A. Moran) (03/19/90)
Dennis akme (hakme@latcs1.oz.au La Trobe Uni. Australia) writes; >Does anyone have any cDNA sequences for chaperonin proteins, or hsp60 and 70 >(especially those with methionine bristles)? >Thanks in advance, > Dennis Hakme. I assume that you are referring to the methionine bristles that are found in the 54K subunit of signal recognition particle (murine) and in an unidentified E. coli protein, ffh (fifty-four homologue). The predicted amino sequences of these proteins suggest that they contain M-domains which consist of amphipathic alpha helices in which the hydrophobic face consists mostly of methionine residues. (Bernstein H.D. et al. 1989, Nat. 340, 482; Rothman, J.E., Nat. 340, 433 (News and Views)). The members of the HSP70 family of proteins do not contain such a domain. There are no clusters of conserved methionines in BiP, hsc70, hsp70, or the mitochondrial HSP70. There are no examples of repeats which contain methionines followed two positions later by arginine or lysine. The predicted amino acid sequences of some of the members of the multigene family contain carboxy-terminal repeats of the motif GGMP but these cannot form alpha helices. We have published a consensus sequence of HSP70's derived from analysis of over 60 different sequences (see Nicholson, R.C. et al. 1990, PNAS 86, 1159). I hope that this information is helpful. -Larry Moran