Genome Sequence of an Obligate Intracellular Pathogen of Humans: <i>Chlamydia trachomatis</i>

TLDR

Chlamydiae lack many biosynthetic capabilities yet retain key metabolic functions from host cells, and their phylogenetic mosaic, including many eukaryote‑derived genes, indicates complex evolution for obligate intracellular parasitism. The 1,042,519‑bp genome of *C.

Abstract

Analysis of the 1,042,519–base pair Chlamydia trachomatis genome revealed unexpected features related to the complex biology of chlamydiae. Although chlamydiae lack many biosynthetic capabilities, they retain functions for performing key steps and interconversions of metabolites obtained from their mammalian host cells. Numerous potential virulence-associated proteins also were characterized. Several eukaryotic chromatin-associated domain proteins were identified, suggesting a eukaryotic-like mechanism for chlamydial nucleoid condensation and decondensation. The phylogenetic mosaic of chlamydial genes, including a large number of genes with phylogenetic origins from eukaryotes, implies a complex evolution for adaptation to obligate intracellular parasitism.