Localization of cytochromes to the outer membrane of anaerobically grown Shewanella putrefaciens MR-1.
AUTOR(ES)
Myers, C R
RESUMO
In gram-negative bacteria, numerous cell functions, including respiration-linked electron transport, have been ascribed to the cytoplasmic membrane. Gram-negative bacteria which use solid substrates (e.g., oxidized manganese or iron) as terminal electron acceptors for anaerobic respiration are presented with a unique problem: they must somehow establish an electron transport link across the outer membrane between large particulate metal oxides and the electron transport chain in the cytoplasmic membrane. When the metal-reducing bacterium Shewanella putrefaciens MR-1 is grown under anaerobic conditions and membrane fractions are purified from cells lysed by an EDTA-lysozyme-polyoxyethylene cetyl ether (Brij 58) protocol, approximately 80% of its membrane-bound cytochromes are localized in its outer membrane. These outer membrane cytochromes could not be dislodged by treatment with chaotropic agents or by increased concentrations of the nonionic detergent Brij 58, suggesting that they are integral membrane proteins. Cytochrome distribution in cells lysed by a French press protocol confirm the localization of cytochromes to the outer membrane of anaerobically grown cells. This novel cytochrome distribution could play a key role in the anaerobic respiratory capabilities of this bacterium, especially in its ability to mediate manganese and iron reduction.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=206023Documentos Relacionados
- Role for Outer Membrane Cytochromes OmcA and OmcB of Shewanella putrefaciens MR-1 in Reduction of Manganese Dioxide
- MtrB Is Required for Proper Incorporation of the Cytochromes OmcA and OmcB into the Outer Membrane of Shewanella putrefaciens MR-1
- Respiration-linked proton translocation coupled to anaerobic reduction of manganese(IV) and iron(III) in Shewanella putrefaciens MR-1.
- Sequence and genetic characterization of etrA, an fnr analog that regulates anaerobic respiration in Shewanella putrefaciens MR-1.
- Genetic Complementation of an Outer Membrane Cytochrome omcB Mutant of Shewanella putrefaciens MR-1 Requires omcB Plus Downstream DNA