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Tryptophan Synthase in Chlamydia
Angela Ghrist
Lori Scott
Background
Intracellular parasites: viruses, bacteria (Chlamydias,
Rickettsias), and protozoa (plasmodia) (CDC website)
Tryptophan biosynthesis genes are found to varying
degrees within the Chlamydiaceae family (“Kegg
pathway” program)
Immune response of humans to Chlamydia infection
involves the release of interferon. This activates an
enzyme that degrades tryptophan, thereby reducing
Chlamydia reproduction inside the host cell
(PubMed)
Tryptophan is an essential amino acid in humans
Taxonomy
Lineage (full): root; cellular organisms; Bacteria; Chlamydiae/Verrucomicrobia group;
Chlamydiae; Chlamydiae (class); Chlamydiales
Chlamydiaceae
– Candidatus Clavochlamydia
• Candidatus Clavochlamydia salmonicola
– Chlamydia
• Chlamydia muridarum
• Chlamydia suis
• Chlamydia trachomatis
– Chlamydophila
• Chlamydophila abortus
• Chlamydophila caviae
• Chlamydophila felis
• Chlamydophila pecorum
• Chlamydophila pneumoniae
• Chlamydophila psittaci
TaxBrowser in NCBI
Available Genomes
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Completed Candidatus Protochlamydia amoebophila UWE25 proteins;
Completed Chlamydia muridarum Nigg proteins;
Completed Chlamydia trachomatis A/HAR-13 proteins;
Completed Chlamydia trachomatis D/UW-3/CX proteins;
Completed Chlamydophila abortus S26/3 proteins;
Completed Chlamydophila caviae GPIC proteins;
Completed Chlamydophila felis Fe/C-56 proteins;
Completed Chlamydophila pneumoniae AR39 proteins;
Completed Chlamydophila pneumoniae CWL029 proteins;
Completed Chlamydophila pneumoniae J138 proteins;
Completed Chlamydophila pneumoniae TW-183 proteins
NCBI – Genomic Biology
Enolase
NCBI - Genome Blast Search and Tree Building
Dendrogram
Enolase
Workbench, ClustalW
Observation
There are multiple serovars of Chlamydia
tachomatis, distinguished by route of
infection.
Question
Are there differences in their trp genes?
Comparison of Ocular (A) and
Genital (D) TrpA Genes
trpA_D
trpA_A
CTTCTACAAAGGGACTTAGATTATCTACGCAGACTAAAAGACGCGGGAATAAATGGTGTG
CTTCTACAAAGGGACTTAGATTATCTACGCAGACTAAAAGACGCGGGAATAAATGGTGTG
trpA_D
trpA_A
TGCGTTATAGATCTTCCAGCACCTTTATCACACGGAGAAAAATCTCCATTTTTTGAAGAT
TGCGTTATAGATCTTCCAGCACCTTTATCACACGGAGAAAAATCTCC---TTTTGAAGAT
trpA_D
trpA_A
CTTTTAGCTGTAGGATTGGATCCTATTTTGCTTATTTCTGCAGGGACAACGCCGGAGCGG
CTTTTAGCTGTAGGATTGGATCCTATTTTGCTTATTTCTGCAGGGACAACGCCGGAGCGG
trpA_D
trpA_A
ATGTCTTTAATACAAGAATACGCAAGAGGCTTTCTGTATTATATCCCATGTCAAGCTACG
ATGTCTTTAATACAAGAACACGCAAGAGGCCTTCTGTATTATATCCCATA-CAAGCTACG
Ocular vs. Genital Tryptophan Synthase
Polymorphisms in Chlamydia trachomatis tryptophan synthase genes
differentiate between genital and ocular isolates
J. Clin. Invest. Harlan D. Caldwell, et al. 111:1757 doi:10.1172/JCI17993
Question
Has the Chlamydia L serovar that causes a
systemic lymph node infection retained the
tryptophan synthase (trpA) gene like the
genital serovars, as opposed to acquiring
nonsense mutations like the ocular serovars?