title: Identification of sequence similarity between 60 kDa and 70 kDa molecular chaperones: evidence for a common evolutionary background?
abstract: Recent findings support the premise that chaperonins (60 kDa stress-proteins) and alpha-subunits of F-type ATPases (alpha-ATPase) are evolutionary related protein families. Two-dimensional gel patterns of synthesized proteins in unstressed and heat-shocked embryonic Drosophila melanogaster SL2 cells revealed that antibodies raised against the alpha-subunit of the F1-ATPase complex from rat liver recognize an inducible p71 member of the 70 kDa stress-responsive protein family. Molecular recognition of this stress-responsive 70 kDa protein by antibodies raised against the F1-ATPase alpha-subunit suggests the possibility of partial sequence similarity within these ATP-binding protein families. A multiple sequence alignment between alpha-ATPases and 60 kDa and 70 kDa molecular chaperones is presented. Statistical evaluation of sequence similarity reveals a significant degree of sequence conservation within the three protein families. The finding suggests a common evolutionary origin for the ATPases and molecular chaperone protein families of 60 kDa and 70 kDa, despite the lack of obvious structural resemblance between them.
authors.affiliation: Departamento de Biologiá Molecular, Universidad Autónoma de Madrid, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Flores
authors.forename: J M
authors.initials: JM
authors.lastname: Cuezva
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D018834:Chaperonin 60 / Q000235:genetics* / Q000276:immunology; D003429:Cross Reactions; D016208:Databases, Factual; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D019143:Evolution, Molecular; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D006180:Proton-Translocating ATPases / Q000235:genetics* / Q000276:immunology; D017386:Sequence Homology, Amino Acid
chemical_list: D018834:Chaperonin 60; D018840:HSP70 Heat-Shock Proteins; D006180:Proton-Translocating ATPases