The Bacillus subtilis cysP gene encodes a novel sulphate permease related to the inorganic phosphate transporter (Pit) family.

MARIA CECILIA MANSILLA; DE-MENDOZA, D.

MICROBIOLOGY-UK

SOC GENERAL MICROBIOLOGY

Año: 2000 vol. 146 p. 815 - 821

1350-0872

Sulphate permeases in the plasma membrane are responsible for uptake ofenvironmental sulphate used in the sulphate assimilation pathway in bacteriaand plants. Here it is reported that the ORF designated cysP, located on theBacillus subtilis chromosome between cysH and five putative genes involved insulphate assimilation, encodes a sulphate permease. cysP is able tocomplement Escherichia coli cysteine auxotrophs with mutations affectingeither the membrane or periplasmic components of the sulphate-thiosulphatepermease. Transport studies with cell suspensions of a cysA97 E. coli straintransformed with a plasmid expressing the B. subtilis cysP gene indicated thatCysP catalyses sulphate uptake. Analysis of the primary sequence showed thatCysP (354 amino acids, estimated molecular mass 24 kDa) is a highlyhydrophobic protein which has 11 putative transmembrane helices. Sequencecomparisons revealed that CysP, together with the phosphate permease ofNeurospora crassa, Pho-4, and E. coli PitA, belongs to the family of relatedtransporters, the inorganic phosphate transporter (Pit) family. Among theputative phosphate permeases, CysP shows a similar size and the same domainorganization as the archaeal transporters. This is the first report of a sulphatepermease in a Gram-positive organism.