4OQ1

Structure of the Streptococcal ancillary pilin

Summary for 4OQ1

• Entry DOI: 10.2210/pdb4oq1/pdb
• Descriptor: Cell wall surface anchor family protein (2 entities in total)
• Functional Keywords: cnab domain, igg-rev fold, pilin protein, cell adhesion
• Biological source: Streptococcus pneumoniae
• Total number of polymer chains: 1
• Total formula weight: 41970.11

Authors

Shaik, M.M.,Di Guilmi, A.M.,Dessen, A. (deposition date: 2014-02-07, release date: 2014-04-23, Last modification date: 2024-11-06)

Primary citation

Shaik, M.M.,Maccagni, A.,Tourcier, G.,Di Guilmi, A.M.,Dessen, A.
Structural Basis of Pilus Anchoring by the Ancillary Pilin RrgC of Streptococcus pneumoniae.
J.Biol.Chem., 289:16988-16997, 2014

PubMed Abstract: Pili are surface-attached, fibrous virulence factors that play key roles in the pathogenesis process of a number of bacterial agents. Streptococcus pneumoniae is a causative agent of pneumonia and meningitis, and the appearance of drug-resistance organisms has made its treatment challenging, especially in developing countries. Pneumococcus-expressed pili are composed of three structural proteins: RrgB, which forms the polymerized backbone, RrgA, the tip-associated adhesin, and RrgC, which presumably associates the pilus with the bacterial cell wall. Despite the fact that the structures of both RrgA and RrgB were known previously, structural information for RrgC was still lacking, impeding the analysis of a complete model of pilus architecture. Here, we report the structure of RrgC to 1.85 Å and reveal that it is a three-domain molecule stabilized by two intradomain isopeptide bonds. RrgC does not depend on pilus-specific sortases to become attached to the cell wall; instead, it binds the preformed pilus to the peptidoglycan by employing the catalytic activity of SrtA. A comprehensive model of the type 1 pilus from S. pneumoniae is also presented.

PubMed: 24755220
DOI: 10.1074/jbc.M114.555854

Experimental method

X-RAY DIFFRACTION (1.85 Å)