The Na+-F1F0-ATPase Operon from Acetobacterium woodii

Abstract

Eight genes (atpI, atpB, atpE 1 , atpE 2 , atpE 3 , atpF, atpH, and atpA) upstream of and contiguous with the previously described genes atpG, atpD, and atpC were cloned from chromosomal DNA of Acetobacterium woodii. Northern blot analysis revealed that the eleven atp genes are transcribed as a polycistronic message. The atp operon encodes the Na ؉ -F 1 F 0 -ATPase of A. woodii, as evident from a comparison of the biochemically derived N termini of the subunits with the amino acid sequences deduced from the DNA sequences. The molecular analysis revealed that all of the F 1 F 0 -encoding genes from Escherichia coli have homologs in the Na ؉ -F 1 F 0 -ATPase operon from A. woodii, despite the fact that only six subunits were found in previous preparations of the enzyme from A. woodii. These results unequivocally prove that the Na ؉

Identification of Subunits a, b, andc 1 from Acetobacterium woodiiNa+-F1F0-ATPase

“…The loss of the proton-binding residue was believed to be the reason for the apparent inability of V 1 V 0 -ATPases to function as ATP synthases under in vivo conditions (16). Western blot analyses verified that atpE 1 was expressed and that the product was not posttranslationally split into two 8-kDa proteolipids (11). However, AtpE 1 was not found in the enzyme purified previously (6).…”

“…Immunoblotting-SDS-PAGE 1 and Western blotting were performed as described previously (11,23). Transfer of proteins from blue native-PAGE to polyvinylidene difluoride membranes was essentially as described (24).…”

“…These studies verified that the anti-c 1 antiserum does not react with subunit c 2/3 . The reaction of the anti-c 2/3 antiserum with subunit c 1 is expected, because 60 and 72% of the amino acids of subunits c 2/3 are conserved in the first and second half of subunit c 1 , respectively (11).…”

Evidence for the Presence of an F-Type ATP Synthase Involved in Sulfate Respiration in Desulfovibrio vulgaris

“…It has been anticipated that F-type ATPases usually hydrolyze ATP to pump out H ϩ in strict anaerobes. However, Propionigenium modestum (11) and Acetobacterium woodii (27), strictly anaerobic bacteria, have Na ϩ -translocating ATP synthases, which synthesize ATP. The generation of an Na ϩ gradient in P. modestum is coupled to a decarboxylation reaction by Na ϩ -translocating membranebound methylmalonyl-coenzyme A (CoA) decarboxylase (11).…”

Halotolerant Cyanobacterium Aphanothece halophytica Contains an Na+-dependent F1F0-ATP Synthase with a Potential Role in Salt-stress Tolerance

“…In C. paradoxum, E. coli, I. tartaricus, and P. modestum, the atp operon consists of nine structural genes, atpI (I), atpB (a), atpE (c), atpF (b), atpH (␦), atpA (␣), atpG (␥), atpD (␤), and atpC (⑀), which are grouped together to form a single transcriptional unit (16 -18, 20, 21). The atp operon in a strictly anaerobic A. woodii consists of 11 genes, including nine genes found in the bacterial atp operons and additional two copies of atpE (c) (22). In addition, the structural genes in cyanobacteria Anabaena strain PCC 7210, Synechococcus strain PCC 6301, and Synechocystis sp.…”