Editor: Jörg Simon
Investigation of direct vs. indirect involvement of the c-type cytochrome MacA in Fe(III) reduction by Geobacter sulfurreducens
Article first published online: 9 JUL 2008
© 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 286, Issue 1, pages 39–44, September 2008
How to Cite
Kim, B.-C. and Lovley, D. R. (2008), Investigation of direct vs. indirect involvement of the c-type cytochrome MacA in Fe(III) reduction by Geobacter sulfurreducens. FEMS Microbiology Letters, 286: 39–44. doi: 10.1111/j.1574-6968.2008.01252.x
- Issue published online: 23 JUL 2008
- Article first published online: 9 JUL 2008
- Received 8 April 2008; accepted 27 May 2008.First published online 9 July 2008.
- Geobacter sulfurreducens;
- c-type cytochrome;
- Fe(III) reduction
The electron transfer pathway to Fe(III) reduction in Geobacter sulfurreducens has been hypothesized to consist of a series of c-type cytochromes. Previous genetic studies suggested that the inner membrane-associated, c-type cytochrome, MacA, was a component of the electron transfer chain leading to Fe(III) reduction in the dissimilatory Fe(III)-reducer, G. sulfurreducens. However, investigation of the expression of OmcB, an outer-membrane c-type cytochrome demonstrated previously to be critical for optimal Fe(III) reduction, revealed that both omcB transcript and protein levels were dramatically reduced in the MacA-deficient mutant. Expression of the omcB gene in trans enabled the MacA-deficient mutant to reduce Fe(III) at a rate that was proportional to the level of omcB expression. These results suggest that MacA is not directly involved in electron transfer to Fe(III) and further confirm the importance of OmcB in Fe(III) reduction by G. sulfurreducens.