Open AccessThe Borrelia burgdorferi flaB promoter has an extended −10 element and includes a T‐rich −35/−10 spacer sequence that is essential for optimal activity
Author(s) -
Gautam Aarti,
Hathaway Marianne,
Ramamoorthy Ramesh
Publication year - 2009
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2009.01542.x
Subject(s) - borrelia burgdorferi , sequence (biology) , biology , microbiology and biotechnology , genetics , antibody
In this study, we investigated the functional elements of the flaB promoter of Borrelia burgdorferi . Promoter function was examined in a high‐passage variant of strain JD1 using a set of 5′ deletions and mutations within the flaB promoter. Expression from the modified flaB promoters was assayed using the gene for green fluorescent protein ( gfp ) as a reporter. Although the −35 element of the promoter stimulated promoter activity, its disruption did not negate expression. Sequences upstream of the −35 had no effect on expression. The −35/−10 spacer region composed of a T‐rich sequence was critical for optimal promoter function. Surprisingly, a cytosine at the −13 site was found to be more favorable for transcription compared with a guanosine at the same site. Based on these results and other characteristics, we propose that the B. burgdorferi flaB promoter is an example of an extended −10 promoter. Further, the T‐rich spacer is a key element of the flaB promoter that contributes to the abundance of the flagellar core protein in Borrelia species.