{PDOC00137} {PS00152; ATPASE_ALPHA_BETA} {BEGIN} ************************************************** * ATP synthase alpha and beta subunits signature * ************************************************** ATP synthase (proton-translocating ATPase) (EC 3.6.3.14) [1,2] is a component of the cytoplasmic membrane of eubacteria, the inner membrane of mitochondria, and the thylakoid membrane of chloroplasts. The ATPase complex is composed of an oligomeric transmembrane sector, called CF(0), and a catalytic core, called coupling factor CF(1). The former acts as a proton channel; the latter is composed of five subunits, alpha, beta, gamma, delta and epsilon. The sequences of subunits alpha and beta are related and both contain a nucleotide-binding site for ATP and ADP. The beta chain has catalytic activity, while the alpha chain is a regulatory subunit. Vacuolar ATPases [3] (V-ATPases) are responsible for acidifying a variety of intracellular compartments in eukaryotic cells. Like F-ATPases, they are oligomeric complexes of a transmembrane and a catalytic sector. The sequence of the largest subunit of the catalytic sector (70 Kd) is related to that of F-ATPase beta subunit, while a 60 Kd subunit, from the same sector, is related to the F-ATPases alpha subunit [4]. Archaebacterial membrane-associated ATPases are composed of three subunits. The alpha chain is related to F-ATPases beta chain and the beta chain is related to F-ATPases alpha chain [4]. A protein highly similar to F-ATPase beta subunits is found [5] in some bacterial apparatus involved in a specialized protein export pathway that proceeds without signal peptide cleavage. This protein is known as fliI in Bacillus and Salmonella, Spa47 (mxiB) in Shigella flexneri, HrpB6 in Xanthomonas campestris and yscN in Yersinia virulence plasmids. In order to detect these ATPase subunits, we took a segment of ten amino-acid residues, containing two conserved serines, as a signature pattern. The first serine seems to be important for catalysis - in the ATPase alpha chain at least - as its mutagenesis causes catalytic impairment. -Consensus pattern: P-[SAP]-[LIV]-[DNH]-{LKGN}-{F}-{S}-S-{DCPH}-S [The first S may be an active site residue] -Sequences known to belong to this class detected by the pattern: ALL, except for the archaebacterium Sulfolobus acidocaldarius ATPase alpha chain where the first Ser is replaced by Gly. -Other sequence(s) detected in Swiss-Prot: 45. -Note: F-ATPase alpha and beta subunits, V-ATPase 70 Kd subunit and the archaebacterial ATPase alpha subunit also contain a copy of the ATP-binding motifs A and B (see ). -Last update: April 2006 / Pattern revised. [ 1] Futai M., Noumi T., Maeda M. "ATP synthase (H+-ATPase): results by combined biochemical and molecular biological approaches." Annu. Rev. Biochem. 58:111-136(1989). PubMed=2528322; DOI=10.1146/annurev.bi.58.070189.000551 [ 2] Senior A.E. "ATP synthesis by oxidative phosphorylation." Physiol. Rev. 68:177-231(1988). PubMed=2892214 [ 3] Nelson N. "Structure, molecular genetics, and evolution of vacuolar H+-ATPases." J. Bioenerg. Biomembr. 21:553-571(1989). PubMed=2531737 [ 4] Gogarten J.P., Kibak H., Dittrich P., Taiz L., Bowman E.J., Bowman B.J., Manolson M.F., Poole R.J., Date T., Oshima T. "Evolution of the vacuolar H+-ATPase: implications for the origin of eukaryotes." Proc. Natl. Acad. Sci. U.S.A. 86:6661-6665(1989). PubMed=2528146 [ 5] Dreyfus G., Williams A.W., Kawagishi I., Macnab R.M. "Genetic and biochemical analysis of Salmonella typhimurium FliI, a flagellar protein related to the catalytic subunit of the F0F1 ATPase and to virulence proteins of mammalian and plant pathogens." J. Bacteriol. 175:3131-3138(1993). PubMed=8491729 -------------------------------------------------------------------------------- PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see https://prosite.expasy.org/prosite_license.html -------------------------------------------------------------------------------- {END}