Table 3. Distribution of key ‘niche-specific’ genes with suspected virulence phenotypes in sequenced Chlamydiaceae genomes.

Genome	Known cytotoxic effectors	Tryptophan metabolism	Nucleotide salvaging
C.pneumoniae AR39	–	tph	add guaBA udk pyrE
C.muridarum MoPn	toxa	–	add guaBA upp
C.trachomatis D	toxb	trpABCR	–
C.caviae GPIC	toxc	trpABCDER kynU prsA tph	add guaBA pyrE

tox, chlamydial toxin; trp, tryptophan biosynthesis; kynU, kynureninase; prsA, ribose-phosphate pyrophosphokinase; tph, tryptophan hydroxylase; add, adenosine deaminase; gua, purine biosynthesis; upp, uracil phosphororibosyl transferase; pyrE, UMP synthase; udk, uridine kinase.

^aThree orthologs of C.caviae tox; each contains glucosyltransferase, UDP-glucose binding and YopT domains.

^bFour ORF fragments; only CT166 contains the glucosyltransferase and UDP-glucose binding domains.

^cSingle tox gene; contains glucosyltransferase, UDP-glucose binding and YopT domains.