Dataset Information

Functional characterization of EngA(MS), a P-loop GTPase of Mycobacterium smegmatis.

ABSTRACT: Bacterial P-loop GTPases belong to a family of proteins that selectively hydrolyze a small molecule guanosine tri-phosphate (GTP) to guanosine di-phosphate (GDP) and inorganic phosphate, and regulate several essential cellular activities such as cell division, chromosomal segregation and ribosomal assembly. A comparative genome sequence analysis of different mycobacterial species indicates the presence of multiple P-loop GTPases that exhibit highly conserved motifs. However, an exact function of most of these GTPases in mycobacteria remains elusive. In the present study we characterized the function of a P-loop GTPase in mycobacteria by employing an EngA homologue from Mycobacterium smegmatis, encoded by an open reading frame, designated as MSMEG_3738. Amino acid sequence alignment and phylogenetic analysis suggest that MSMEG_3738 (termed as EngA(MS)) is highly conserved in mycobacteria. Homology modeling of EngA(MS) reveals a cloverleaf structure comprising of ?/? fold typical to EngA family of GTPases. Recombinant EngA(MS) purified from E. coli exhibits a GTP hydrolysis activity which is inhibited by the presence of GDP. Interestingly, the EngA(MS) protein is co-eluted with 16S and 23S ribosomal RNA during purification and exhibits association with 30S, 50S and 70S ribosomal subunits. Further studies demonstrate that GTP is essential for interaction of EngA(MS) with 50S subunit of ribosome and specifically C-terminal domains of EngA(MS) are required to facilitate this interaction. Moreover, EngA(MS) devoid of N-terminal region interacts well with 50S even in the absence of GTP, indicating a regulatory role of the N-terminal domain in EngA(MS)-50S interaction.

SUBMITTER: Agarwal N

PROVIDER: S-EPMC3323550 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

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Functional characterization of EngA(MS), a P-loop GTPase of Mycobacterium smegmatis.

Agarwal Nisheeth N Pareek Madhu M Thakur Preeti P Pathak Vibha V

PloS one 20120410 4

Bacterial P-loop GTPases belong to a family of proteins that selectively hydrolyze a small molecule guanosine tri-phosphate (GTP) to guanosine di-phosphate (GDP) and inorganic phosphate, and regulate several essential cellular activities such as cell division, chromosomal segregation and ribosomal assembly. A comparative genome sequence analysis of different mycobacterial species indicates the presence of multiple P-loop GTPases that exhibit highly conserved motifs. However, an exact function of ...[more]

PMID: 22506030

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Project description:Mycobacterium smegmatis SigF is a group III sigma factor. Its ortholog in M. tuberculosis is reported to have role in regulation and function of cell wall components. In present study we have created an M. smegmatis M-NM-^TsigF mutant by allele exchange method. M. smegmatis sigF mutant shows non pigmented phenotype and is more sensitive to hydrogen peroxide generated oxidative stress. DNA microarray analysis of M. smegmatis wild type and M-NM-^TsigF mutant suggests that SigF in this species controls the expression of several energy and central intermediary metabolism genes along with regulation of carotenoid biosynthesis. Gene expression patterns of M.smegmatis wild type and M-NM-^TsigF mutant strains were compared at two growth stages i.e. log (OD600 ~1.4) and stationary (OD600 ~3.0). M. smegmatis strains were grown in DifcoTM MiddleBrook 7H9 broth base (BD Biosciences, Sparks, MD, USA) with 0.2% glycerol (v/v) and 0.05% Tween-80 (Sigma-Aldrich, St Louis, MO, USA) supplemented with 10% albumen dextrose catalase (BD Biosciences) (v/v) at 37 0C with continuous shaking. Total RNA was isolated using Trizole (Invitrogen) method and labelled with cyanine 3 (Cy3) as per Agilent 1-color labelling protocol (Version 5.5, February 2007). Six hundred nanograms of each Cy3 labelled samples were fragmented and hybridized. Fragmentation of labeled cRNA and hybridization were performed using Gene Expression Hybridization kit (Agilent Technologies). Hybridization was carried out in AgilentM-bM-^@M-^Ys Surehyb Chambers at 65 0C for 16 h. The hybridized slides were washed using Agilent Gene Expression wash buffers and scanned using the Agilent Microarray Scanner G Model G2565BA at 5 micron resolution. Feature extracted data was analysed using GeneSpring GX v 7.3.1 software from Agilent. Normalization of the data was done in GeneSpring GX using the recommended one color Per Chip and Per Gene Data Transformation. Set measurements less than 0.01 to 0.01 per chip, normalize to 50th percentile per gene, and normalize to specific samples.

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Dataset Information

Functional characterization of EngA(MS), a P-loop GTPase of Mycobacterium smegmatis.

Publications

Functional characterization of EngA(MS), a P-loop GTPase of Mycobacterium smegmatis.

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