The Na(+)-F(1)F(0)-ATPase operon from Acetobacterium woodii. Operon structure and presence of multiple copies of atpE which encode proteolipids of 8- and 18-kda.
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(+)-ATPase from A. woodii is an enzyme of the F(1)F(0) class. Most interestingly, the gene encoding the proteolipid underwent quadruplication. Two gene copies (atpE(2) and atpE(3)) encode identical 8-kDa proteolipids. Two additional gene copies were fused to form the atpE(1) gene. Heterologous expression experiments as well as immunolabeling studies with native membranes revealed that atpE(1) encodes a duplicated 18-kDa proteolipid. This is the first demonstration of multiplication and fusion of proteolipid-encoding genes in F(1)F(0)-ATPase operons. Furthermore, AtpE(1) is the first duplicated proteolipid ever found to be encoded by an F(1)F(0)-ATPase operon.
Rahlfs
S
S
Institut für Mikrobiologie und Genetik der Georg-August-Universität, Grisebachstrasse 8, 37077 Göttingen, Germany.
Aufurth
S
S
Müller
V
V
D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport; D015152:Blotting, Northern; D004926:Escherichia coli / Q000235:genetics; D018628:Gene Dosage; D020440:Gene Duplication; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D016987:Gram-Positive Rods / Q000201:enzymology / Q000235:genetics*; D015151:Immunoblotting; D008565:Membrane Proteins / Q000378:metabolism; D008566:Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009876:Operon / Q000235:genetics*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011510:Proteolipids / Q000235:genetics; D006180:Proton-Translocating ATPases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic
D008565:Membrane Proteins; D020033:Protein Isoforms; D011510:Proteolipids; D012329:RNA, Bacterial; D011993:Recombinant Fusion Proteins; D006180:Proton-Translocating ATPases