Identi¢cation of a novel mycobacterial transcriptional regulator and its involvement in growth rate dependence and stringent control

Kamalanathan, V and Ramachandran, Geetha and Narayanan, Sujatha and Vasan, S K and Narayanan, P R (2002) Identi¢cation of a novel mycobacterial transcriptional regulator and its involvement in growth rate dependence and stringent control. FEMS Microbiology Letters , 209 (2). pp. 261-266. ISSN Print: 0378-1097; Online: 1574-6968

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Abstract

A novel transcriptional regulator has been identified in the 400-bp upstream region of the guaA gene of Mycobacterium tuberculosis H37Rv that promotes the expression of lacZ gene in Mycobacterium smegmatis mc2155 and M. tuberculosis H37Rv but not in Escherichia coli DH5K. PCR-mediated deletion mutagenesis and cloning identified a 120-bp fragment upstream from the guaA gene to be the actual regulator. Primer extension analysis mapped the transcription start site to be the first ‘G’ residue of the translation start codon GTG of the guaA gene. Electrophoretic mobility shift assay showed strong binding of M. smegmatis RNA polymerase holoenzyme to the 400-bp fragment that expresses lacZ in mycobacterial species and a weak binding to the 280-bp fragment that expresses only in E. coli DH5K. Both promoter recombinants revealed varied response in the presence of purine nucleotides and exhibited down-regulation when subjected to amino acid starvation.

Item Type:	Article
Uncontrolled Keywords:	Promoter; Transcriptional regulator; Stringent response; Induction
Subjects:	Tuberculosis > Laboratory Research > Immunological
Divisions:	Basic Science Research > Immunology
Depositing User:	Dr. Rathinasabapati R
Date Deposited:	08 Nov 2013 07:11
Last Modified:	10 Mar 2016 04:35
URI:	http://eprints.nirt.res.in/id/eprint/561

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