Dissection of the caffeate respiratory chain in the acetogen Acetobacterium woodii: identification of an Rnf-type NADH dehydrogenase as a potential coupling site.

ABSTRACT: The anaerobic acetogenic bacterium Acetobacterium woodii couples caffeate reduction with electrons derived from hydrogen to the synthesis of ATP by a chemiosmotic mechanism with sodium ions as coupling ions, a process referred to as caffeate respiration. We addressed the nature of the hitherto unknown enzymatic activities involved in this process and their cellular localization. Cell extract of A. woodii catalyzes H(2)-dependent caffeate reduction. This reaction is strictly ATP dependent but can be activated also by acetyl coenzyme A (CoA), indicating that there is formation of caffeyl-CoA prior to reduction. Two-dimensional gel electrophoresis revealed proteins present only in caffeate-grown cells. Two proteins were identified by electrospray ionization-mass spectrometry/mass spectrometry

SUBMITTER: Imkamp F 

PROVIDER: S-EPMC2168664 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature