Dataset Information

Role for GrgA in Regulation of ?²⁸-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

ABSTRACT: The obligate intracellular bacterial pathogen Chlamydia trachomatis has a unique developmental cycle consisting of two contrasting cellular forms. Whereas the primary Chlamydia sigma factor, ?⁶⁶, is involved in the expression of the majority of chlamydial genes throughout the developmental cycle, expression of several late genes requires the alternative sigma factor, ?²⁸ In prior work, we identified GrgA as a Chlamydia-specific transcription factor that activates ?⁶⁶-dependent transcription by binding DNA and interacting with a nonconserved region (NCR) of ?⁶⁶ Here, we extend these findings by showing GrgA can also activate ?²⁸-dependent transcription through direct interaction with ?²⁸ We measure the binding affinity of GrgA for both ?⁶⁶ and ?²⁸, and we identify regions of GrgA important for ?²⁸-dependent transcription. Similar to results obtained with ?⁶⁶, we find that GrgA's interaction with ?²⁸ involves an NCR located upstream of conserved region 2 of ?²⁸ Our findings suggest that GrgA is an important regulator of both ?⁶⁶- and ?²⁸-dependent transcription in C. trachomatis and further highlight NCRs of bacterial RNA polymerase as targets for regulatory factors unique to particular organisms.IMPORTANCE Chlamydia trachomatis is the number one sexually transmitted bacterial pathogen worldwide. A substantial proportion of C. trachomatis-infected women develop infertility, pelvic inflammatory syndrome, and other serious complications. C. trachomatis is also a leading infectious cause of blindness in underdeveloped countries. The pathogen has a unique developmental cycle that is transcriptionally regulated. The discovery of an expanded role for the Chlamydia-specific transcription factor GrgA helps us understand the progression of the chlamydial developmental cycle.

SUBMITTER: Desai M

PROVIDER: S-EPMC6153665 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

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Role for GrgA in Regulation of σ28-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

Desai Malhar M Wurihan Wurihan W Di Rong R Fondell Joseph D JD Nickels Bryce E BE Bao Xiaofeng X Fan Huizhou H

Journal of bacteriology 20180924 20

The obligate intracellular bacterial pathogen Chlamydia trachomatis has a unique developmental cycle consisting of two contrasting cellular forms. Whereas the primary Chlamydia sigma factor, σ66, is involved in the expression of the majority of chlamydial genes throughout the developmental cycle, expression of several late genes requires the alternative sigma factor, σ28 In prior work, we identified GrgA as a Chlamydia-specific transcription factor that ...[more]

PMID: 30061357

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Project description:BackgroundThe obligate intracellular growing bacterium Chlamydia trachomatis causes diseases like trachoma, urogenital infection and lymphogranuloma venereum with severe morbidity. Several serovars and genotypes have been identified, but these could not be linked to clinical disease or outcome. The related Chlamydophila pneumoniae, of which no subtypes are recognized, causes respiratory infections worldwide. We developed a multi locus sequence typing (MLST) scheme to understand the population genetic structure and diversity of these species and to evaluate the association between genotype and disease.ResultsA collection of 26 strains of C. trachomatis of different serovars and clinical presentation and 18 strains of C. pneumoniae were included in the study. For comparison, sequences of C. abortus, C. psittaci, C. caviae, C. felis, C. pecorum (Chlamydophila), C. muridarum (Chlamydia) and of Candidatus protochlamydia and Simkania negevensis were also included. Sequences of fragments (400 - 500 base pairs) from seven housekeeping genes (enoA, fumC, gatA, gidA, hemN, hlfX, oppA) were analysed. Analysis of allelic profiles by eBurst revealed three non-overlapping clonal complexes among the C. trachomatis strains, while the C. pneumoniae strains formed a single group. An UPGMA tree produced from the allelic profiles resulted in three groups of sequence types. The LGV strains grouped in a single cluster, while the urogenital strains were distributed over two separated groups, one consisted solely of strains with frequent occurring serovars (E, D and F). The distribution of the different serovars over the three groups was not consistent, suggesting exchange of serovar encoding ompA sequences. In one instance, exchange of fumC sequences between strains of different groups was observed. Cluster analyses of concatenated sequences of the Chlamydophila and Chlamydia species together with those of Candidatus Protochlamydia amoebophila and Simkania negevensis resulted in a tree identical to that obtained with 23S RNA gene sequences.ConclusionThese data show that C. trachomatis and C. pneumoniae are highly uniform. The difference in genetic diversity between C. trachomatis and C. pneumoniae is in concordance with a later assimilation to the human host of the latter. Our data supports the taxonomy of the order of Chlamydiales.

Dataset Information

Role for GrgA in Regulation of ?²⁸-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

Publications

Role for GrgA in Regulation of σ<sup>28</sup>-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

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Dataset Information

Role for GrgA in Regulation of ?28-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

Publications

Role for GrgA in Regulation of σ<sup>28</sup>-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Role for GrgA in Regulation of ?²⁸-Dependent Transcription in the Obligate Intracellular Bacterial Pathogen Chlamydia trachomatis.