A LysR-family transcriptional regulator required for virulence in Brucella abortus is highly conserved among the alpha-proteobacteria

作者：Sheehan Lauren M; Budnick James A; Blanchard Catlyn; Dunman Paul M; Caswell Clayton C^*

来源：Molecular Microbiology, 2015, 98(2): 318-328.

DOI：10.1111/mmi.13123

Small RNAs are principal elements of bacterial gene regulation and physiology. Twosmall RNAs in Brucella abortus, AbcR1 and AbcR2, are required for wild- type virulence. Examination of the abcR loci revealed the presence of a gene encoding a LysR- type transcriptional regulator flanking abcR2 on chromosome 1. Deletion of this lysR gene ( bab1_ 1517) resulted in the complete loss of abcR2 expression while no difference in abcR1 expression was observed. The B. abortus bab1_ 1517 mutant strain was significantly attenuated in macrophages and mice, and bab1_ 1517 was subsequently named vtlR for virulence- associated transcriptional LysR- family regulator. Microarray analysis revealed three additional genes encoding small hypothetical proteins also under the control of VtlR. Electrophoretic mobility shift assays demonstrated that VtlR binds directly to the promoter regions of abcR2 and the three hypothetical protein- encoding genes, and DNase I footprint analysis identified the specific nucleotide sequence in these promoters that VtlR binds to and drives gene expression. Strikingly, orthologs of VtlR are encoded in a wide range of host- associated alpha- proteobacteria, and it is likely that the VtlR genetic system represents a common regulatory circuit critical for host- bacterium interactions.

• 出版日期2015-10
• 单位美国弗吉尼亚理工大学(Virginia Tech)