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Amide bonds assemble pili on the surface of bacilli.

ABSTRACT: Pilin precursors are the building blocks of pili on the surface of Gram-positive bacteria; however, the assembly mechanisms of these adhesive fibers are unknown. Here, we describe the chemical bonds that assemble BcpA pilin subunits on the surface of Bacillus cereus. Sortase D cleaves BcpA precursor between the threonine (T) and the glycine (G) residues of its LPXTG sorting signal and catalyzes formation of an amide bond between threonine (T) of the sorting signal and lysine (K) in the YPKN motif of another BcpA subunit. Three CNA B domains of BcpA generate intramolecular amide bonds, and one of these contributes also to pilus formation. Conservation of catalysts and structural elements in pilin precursors in Gram-positive bacteria suggests a universal mechanism of fiber assembly.

SUBMITTER: Budzik JM

PROVIDER: S-EPMC2481347 | biostudies-other | 2008 Jul

REPOSITORIES: biostudies-other

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Amide bonds assemble pili on the surface of bacilli.

Budzik Jonathan M JM Marraffini Luciano A LA Souda Puneet P Whitelegge Julian P JP Faull Kym F KF Schneewind Olaf O

Proceedings of the National Academy of Sciences of the United States of America 20080711 29

Pilin precursors are the building blocks of pili on the surface of Gram-positive bacteria; however, the assembly mechanisms of these adhesive fibers are unknown. Here, we describe the chemical bonds that assemble BcpA pilin subunits on the surface of Bacillus cereus. Sortase D cleaves BcpA precursor between the threonine (T) and the glycine (G) residues of its LPXTG sorting signal and catalyzes formation of an amide bond between threonine (T) of the sorting signal and lysine (K) in the YPKN moti ...[more]

PMID: 18621716

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