The following text describes a protein:
Function:
Component of the RavA-ViaA chaperone complex, which may act on the membrane to optimize the function of some of the respiratory chains. RavA functions as an ATPase; The RavA-ViaA system is involved in the regulation of two respiratory complexes, the fumarate reductase (Frd) electron transport complex and the NADH-quinone oxidoreductase complex (NDH-1 or Nuo complex). It modulates the activity of the Frd complex, signifying a potential regulatory function during bacterial anaerobic respiration with fumarate as the terminal electron acceptor. Interaction of RavA-ViaA with FrdA results in a decrease in Frd activity. It also interacts with the Nuo complex, known to be involved in both the aerobic and the anaerobic respiration. The RavA-ViaA system binds to specific membrane phospholipids, and might chaperone certain respiratory complexes by acting on lipid microdomains in which these complexes are inserted. The RavA-ViaA system also plays a negative role in bacterial persistence upon treatment with antibiotics through the association of the chaperone complex with Frd. It sensitizes cells to sublethal concentrations of aminoglycoside (AG) antibiotics. The system can facilitate uptake of AG across the membrane when cells are in a low energy state. It sensitizes cells to AG through a proton motive force-dependent mechanism. Under fumarate respiration conditions, it sensitizes cells to AG via a FrdA-dependent mechanism. It does not sensitize cells grown under nitrate respiration to gentamicin. In addition, RavA is involved in the bacterial acid stress response. Acts by binding to the inducible lysine decarboxylase CadA/LdcI, a key enzyme in the acid stress response, which reduces binding of CadA/LdcI to its potent inhibitor, the stringent response alarmone ppGpp, and thus modulates CadA/LdcI activity. RavA also has GTPase activity in vitro. GTP hydrolysis is much slower than ATP hydrolysis at lower enzyme/substrate concentrations but reaches comparable levels with increasing amounts of enzyme/substrate.
Subcellular Localization:
Cytoplasm. Cell inner membrane; Peripheral membrane protein; Cytoplasmic side. Note=Localizes to the membrane via interaction with specific lipids.
Domain:
A protomer can be divided into three domains: the N-terminal domain is the AAA+ module, which is composed of two subdomains, the alpha-beta-alpha subdomain and the all-alpha subdomain. The second domain is a discontinuous triple-helical domain. The third domain, named the LARA domain, contains a compact antiparallel beta-barrel-like domain forming a unique fold. Binding between ViaA and the triple-helical bundle domain of RavA results in the enhancement of the ATPase activity of RavA. The LARA domain mediates RavA-CadA/LdcI interactions.
Sequence:
MAHPHLLAERISRLSSSLEKGLYERSHAIRLCLLAALSGESVFLLGPPGIAKSLIARRLKFAFQNARAFEYLMTRFSTPEEVFGPLSIQALKDEGRYERLTSGYLPEAEIVFLDEIWKAGPAILNTLLTAINERQFRNGAHVEKIPMRLLVAASNELPEADSSLEALYDRMLIRLWLDKVQDKANFRSMLTSQQDENDNPVPDALQVTDEEYERWQKEIGEITLPDHVFELIFMLRQQLDKLPDAPYVSDRRWKKAIRLLQASAFFSGRSAVAPVDLILLKDCLWYDAQSLNLIQQQIDVLMTGHAWQQQGMLTRLGAIVQRHLQLQQQQSDKTALTVIRLGGIFSRRQQYQLPVNVTASTLTLLLQKPLKLHDMEVVHISFERSALEQWLSKGGEIRGKLNGIGFAQKLNLEVDSAQHLVVRDVSLQGSTLALPGSSAEGLPGEIKQQLEELESDWRKQHALFSEQQKCLFIPGDWLGRIEASLQDVGAQIRQAQQC