Format

Send to

Choose Destination
See comment in PubMed Commons below
J Biol Chem. 2013 Jul 26;288(30):22068-79. doi: 10.1074/jbc.M113.475012. Epub 2013 May 23.

Structure of the Chlamydia trachomatis immunodominant antigen Pgp3.

Author information

1
Department of Biochemistry, University of Texas Health Science Center, San Antonio, Texas 78229, USA.

Abstract

Chlamydia trachomatis infection is the most common sexually transmitted bacterial disease. Left untreated, it can lead to ectopic pregnancy, pelvic inflammatory disease, and infertility. Here we present the structure of the secreted C. trachomatis protein Pgp3, an immunodominant antigen and putative virulence factor. The ∼84-kDa Pgp3 homotrimer, encoded on a cryptic plasmid, consists of globular N- and C-terminal assemblies connected by a triple-helical coiled-coil. The C-terminal domains possess folds similar to members of the TNF family of cytokines. The closest Pgp3 C-terminal domain structural homologs include a lectin from Burkholderia cenocepacia, the C1q component of complement, and a portion of the Bacillus anthracis spore surface protein BclA, all of which play roles in bioadhesion. The N-terminal domain consists of a concatenation of structural motifs typically found in trimeric viral proteins. The central parallel triple-helical coiled-coil contains an unusual alternating pattern of apolar and polar residue pairs that generate a rare right-handed superhelical twist. The unique architecture of Pgp3 provides the basis for understanding its role in chlamydial pathogenesis and serves as the platform for its optimization as a potential vaccine antigen candidate.

KEYWORDS:

Bacterial Pathogenesis; Beta-Helix; Beta-Propeller; Chlamydia; Helical Coiled-coil; Immunology; Pgp3; Sexually Transmitted Disease; Tumor Necrosis Factor (TNF); X-ray Crystallography

PMID:
23703617
PMCID:
PMC3724661
DOI:
10.1074/jbc.M113.475012
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center