Molecular analysis of an operon in Bacillus subtilis encoding a novel ABC transporter with a role in exoprotein production, sporulation and competence.
The levels of exoamylase and other exoenzymes of Bacillus subtilis are pleiotropically decreased by the ecs-26 (prs-26) and ecs-13 (prs-13) mutations. These mutations also cause a competence- and sporulation-deficient phenotype. In the present work, the ecs locus, which has been defined by the ecs-26 and ecs-13 mutations, was cloned and sequenced. Sequence analysis revealed a putative operon of three ORFs (ecsA, ecsB and ecsC). ecsA can encode a putative polypeptide of 248 amino acid residues containing an ATP-binding site. The polypeptide shows about 30% sequence similarity with the ATP-binding components of numerous membrane transporters of the ABC-type (ATP-binding cassette transporters or traffic ATPases). The ecs-26 mutation was found to result from a transition of one base pair chaning the glycine164 of EcsA to a glutamic acid residue in the vicinity of the putative ATP-binding pocket. ecsB was predicted to encode a hydrophobic protein with six membrane-spanning helices in a pattern found in other hydrophobic components of ABC transporters. The properties deduced for the ecsA and ecsB gene products are consistent with the interpretation that ecs encodes a novel ABC-type membrane transporter of B. subtilis. The third ORF, ecsC, can encode a putative polypeptide of 237 amino acid residues. The polypeptide does not resemble components of ABC transporters.
Leskelä
Soile
S
National Public Health Institute, Department of Bacterial Vaccine Research and Molecular Bacteriology, Mannerheimintie 166, FIN-00300 Helsinki, Finland.
Kontinen
Vesa P
VP
National Public Health Institute, Department of Bacterial Vaccine Research and Molecular Bacteriology, Mannerheimintie 166, FIN-00300 Helsinki, Finland.
Sarvas
Matti
M
National Public Health Institute, Department of Bacterial Vaccine Research and Molecular Bacteriology, Mannerheimintie 166, FIN-00300 Helsinki, Finland.
D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001692:Biological Transport; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013171:Spores, Bacterial / Q000502:physiology; D014170:Transformation, Genetic
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C098149:EcsA protein, Bacillus subtilis; C098150:EcsB protein, Bacillus subtilis; C098151:EcsC protein, Bacillus subtilis