Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rickettsiae are gram-negative, obligately intracellular bacteria responsible for arthropod-borne spotted fevers and typhus. Experimental studies have delineated a cluster of naturally rifampin-resistant spotted fever group species. We sequenced the 4, 122- to 4,125-bp RNA polymerase beta-subunit-encoding gene (rpoB) from typhus and spotted fever group representatives and obtained partial sequences for all naturally rifampin-resistant species. A single point mutation resulting in a phenylalanine-to-leucine change at position 973 of the Rickettsia conorii rpoB sequence and present in all the rifampin-resistant species was absent in all the rifampin-susceptible species. rpoB-based phylogenetic relationships among these rickettsial species yielded topologies which were in accordance with previously published phylogenies.
 ...
PMID:Characterization of mutations in the rpoB gene in naturally rifampin-resistant Rickettsia species. 1050 14

Rickettsia felis is maintained transovarially in Ctenocephalides felis fleas in a widespread geographic distribution and is transmitted to humans and animals, including opossums. This rickettsia is phylogenetically a member of the spotted fever group, most closely related to Rickettsia akari and R. australis. An unusual feature of this rickettsia is that the gene for the outer membrane protein A (OmpA) is interrupted by stop codons. To determine if this putatively dying gene is expressed, mRNA was extracted from laboratory-maintained, R. felis-infected cat fleas. Reverse transcriptase-polymerase chain reaction amplification of three segments of the ompA gene indicated that mRNA of ompA is actively transcribed in fleas. The cDNA sequences expressed represented mRNA of the first 1860-basepair segment of ompA, which includes domains I and II, part of domain III, the region from site 1836 to site 2180, despite the presence of several stop codons, and the open reading frame from site 2788 to site 3837. The detected sequences showed several differences in the amino acid composition when compared with the previously reported sequence.
 ...
PMID:Transcription of the Rickettsia felis ompA gene in naturally infected fleas. 1622 5