@article {484, title = {Genomic analysis reveals epistatic silencing of "expensive" genes in Escherichia coli K-12. [Next Generation Genomics facility]}, journal = {Mol Biosyst}, volume = {9}, year = {2013}, month = {2013 Aug}, pages = {2021-33}, abstract = {

A barrier for horizontal gene transfer is high gene expression, which is metabolically expensive. Silencing of horizontally-acquired genes in the bacterium Escherichia coli is caused by the global transcriptional repressor H-NS. The activity of H-NS is enhanced or diminished by other proteins including its homologue StpA, and Hha and YdgT. The interconnections of H-NS with these regulators and their role in silencing gene expression in E. coli are not well understood on a genomic scale. In this study, we use transcriptome sequencing to show that there is a bi-layered gene silencing system - involving the homologous H-NS and StpA - operating on horizontally-acquired genes among others. We show that H-NS-repressed genes belong to two types, termed "epistatic" and "unilateral". In the absence of H-NS, the expression of "epistatically controlled genes" is repressed by StpA, whereas that of "unilaterally controlled genes" is not. Epistatic genes show a higher tendency to be non-essential and recently acquired, when compared to unilateral genes. Epistatic genes reach much higher expression levels than unilateral genes in the absence of the silencing system. Finally, epistatic genes contain more high affinity H-NS binding motifs than unilateral genes. Therefore, both the DNA binding sites of H-NS as well as the function of StpA as a backup system might be selected for silencing highly transcribable genes.

}, keywords = {Binding Sites, DNA-Binding Proteins, Epistasis, Genetic, Escherichia coli K12, Escherichia coli Proteins, Fimbriae Proteins, Gene Expression Regulation, Bacterial, Gene Silencing, Gene Transfer, Horizontal, Genome, Bacterial, Molecular Chaperones, Protein Binding, Repressor Proteins, Sequence Analysis, DNA, Transcription, Genetic, Transcriptome}, issn = {1742-2051}, doi = {10.1039/c3mb70035f}, author = {Srinivasan, Rajalakshmi and Chandraprakash, Deepti and Krishnamurthi, Revathy and Singh, Parul and Scolari, Vittore F and Krishna, Sandeep and Seshasayee, Aswin Sai Narain} } @article {490, title = {Genome sequence of the halotolerant bacterium Imtechella halotolerans K1T. [Next Generation Genomics facility]}, journal = {J Bacteriol}, volume = {194}, year = {2012}, month = {2012 Jul}, pages = {3731}, abstract = {

We report the 3.087-Mb genome sequence of Imtechella halotolerans K1(T), isolated from an estuarine water sample collected from Kochi, Kerala, India. Strain K1 was recently reported as a novel genus of the family Flavobacteriaceae.

}, keywords = {Gene Expression Regulation, Bacterial, Genome, Bacterial, Gram-Negative Aerobic Bacteria, Molecular Sequence Data}, issn = {1098-5530}, doi = {10.1128/JB.00506-12}, author = {Kumar, Shailesh and Vikram, Surendra and Subramanian, Srikrishna and Raghava, Gajendra Pal Singh and Pinnaka, Anil Kumar} } @article {489, title = {Genome sequence of the marine bacterium Marinilabilia salmonicolor JCM 21150T. [Next Generation Genomics facility]}, journal = {J Bacteriol}, volume = {194}, year = {2012}, month = {2012 Jul}, pages = {3746}, abstract = {

We report the 4.98-Mb genome sequence of Marinilabilia salmonicolor JCM 21150(T), which was isolated from marine mud in the year 1961. The draft genome of strain Marinilabilia salmonicolor JCM 21150(T) contains 4,982,627 bp with a G+C content of 41.92\% and 4,227 protein coding genes, 52 tRNAs, and 3 rRNAs.

}, keywords = {Bacteria, Gene Expression Regulation, Bacterial, Genome, Bacterial, Molecular Sequence Data}, issn = {1098-5530}, doi = {10.1128/JB.00649-12}, author = {Kumar, Shailesh and Subramanian, Srikrishna and Raghava, Gajendra Pal Singh and Pinnaka, Anil Kumar} }