A single gene (tts) located outside the cap locus directs the formation of Streptococcus pneumoniae type 37 capsular polysaccharide. Type 37 pneumococci are natural, genetically binary strains.

ABSTRACT: The molecular aspects of the type 37 pneumococcal capsular biosynthesis, a homopolysaccharide composed of sophorosyl units (beta-d-Glc-(1-->2)-beta-d-Glc) linked by beta-1,3 bonds, have been studied. Remarkably, the biosynthesis of the type 37 capsule is driven by a single gene (tts) located far apart from the cap locus responsible for capsular formation in all of the types characterized to date in Streptococcus pneumoniae. However, a cap37 locus virtually identical to the cap33f cluster has been found in type 37 strains, although some of its genes are inactivated by mutations. The tts gene has been sequenced and its transcription start point determined. Tts shows sequence motifs characteristic of cellulose synthases and other beta-glycosyltransferases. Insertion of the tts gene into the p

SUBMITTER: Llull D 

PROVIDER: S-EPMC2195575 | biostudies-literature | 1999 Jul

REPOSITORIES: biostudies-literature