Purification and properties of valyl-tRNA synthetase from Mycobacterium smegmatis

Natarajan, Viswanathan; Gopinathan, K. P.

doi:10.1016/0005-2744(79)90292-4

Cited by 6 publications

(3 citation statements)

References 16 publications

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“…In this part we chose two genes that were detected as putative HGT-derived with significant support by our method but are also present in all selected strains, and additionally, perform important functions within the bacterial cell: valS and speG . valS ([ 50 , 51 ]) is a Valyl-tRNA synthetase, an amino-acyl tRNA synthetase which catalyzes the attachment of valine to tRNA(Val). tRNA amino-acyl synthetases have been shown to frequently being horizontally transferred in evolution[ 52 ].…”

Section: Resultsmentioning

confidence: 99%

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Detecting Horizontal Gene Transfer between Closely Related Taxa

et al. 2015

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Horizontal gene transfer (HGT), the transfer of genetic material between organisms, is crucial for genetic innovation and the evolution of genome architecture. Existing HGT detection algorithms rely on a strong phylogenetic signal distinguishing the transferred sequence from ancestral (vertically derived) genes in its recipient genome. Detecting HGT between closely related species or strains is challenging, as the phylogenetic signal is usually weak and the nucleotide composition is normally nearly identical. Nevertheless, there is a great importance in detecting HGT between congeneric species or strains, especially in clinical microbiology, where understanding the emergence of new virulent and drug-resistant strains is crucial, and often time-sensitive.We developed a novel, self-contained technique named Near HGT, based on the synteny index, to measure the divergence of a gene from its native genomic environment and used it to identify candidate HGT events between closely related strains. The method confirms candidate transferred genes based on the constant relative mutability (CRM). Using CRM, the algorithm assigns a confidence score based on “unusual” sequence divergence. A gene exhibiting exceptional deviations according to both synteny and mutability criteria, is considered a validated HGT product. We first employed the technique to a set of three E. coli strains and detected several highly probable horizontally acquired genes. We then compared the method to existing HGT detection tools using a larger strain data set.When combined with additional approaches our new algorithm provides richer picture and brings us closer to the goal of detecting all newly acquired genes in a particular strain.

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Section: Resultsmentioning

confidence: 99%

“…valS ([ 50 , 51 ]) is a Valyl-tRNA synthetase, an amino-acyl tRNA synthetase which catalyzes the attachment of valine to tRNA(Val). tRNA amino-acyl synthetases have been shown to frequently being horizontally transferred in evolution[ 52 ].…”

Section: Resultsmentioning

confidence: 99%

Detecting Horizontal Gene Transfer between Closely Related Taxa

et al. 2015

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“…Valyl-tRNA synthetase has been purified to homogeneity from a number of sources. Bacterial valyl-tRNA synthetases are monomeric (Yaniv & Gros, 1969; Samuelsson & Lundvik, 1978;Kohda et al, 1984) except for the slow growing Mycobacterium smegmatis, where a subunit structure of the a4 type was reported (Natarajan & Gopinathan, 1979). Yeast valyl-tRNA synthetase was also found to be a monomer with a molecular weight of 120 000 (Kern et al, 1975).…”

Section: Discussionmentioning

confidence: 99%

Mammalian high-molecular-weight and monomeric forms of valyl-tRNA synthetase

Godar

Yang²

1988

Biochemistry

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Valyl-tRNA synthetase from rat liver sediments at 15.5 S with a Stokes radius of 90 A, corresponding to a native molecular weight of 585,000. Purification of valyl-tRNA synthetase to homogeneity by a combination of conventional and affinity column chromatography yields a fully active monomeric form of valyl-tRNA synthetase with a sedimentation coefficient of 7.7 S and a Stokes radius of 45 A. The subunit molecular weight of the monomeric valyl-tRNA synthetase is 140,000, as determined by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. In the presence of 400 mM KCl, the purified monomeric valyl-tRNA synthetase associates to a high molecular weight form. The high molecular weight valyl-tRNA synthetase in the homogenate can be readily converted to the monomeric form by controlled trypsinization. The kinetic parameters of the two forms are nearly identical. The results suggest that the high molecular weight valyl-tRNA synthetase is a homotypic tetramer and converts to the monomeric valyl-tRNA synthetase after the cleavage of a small peptide.

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Stimulation of valyl- and isoleucyl-tRNA synthetase reactions by polyamines

Natarajan

Gopinathan

1979

J Biosci

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Purification and properties of valyl-tRNA synthetase from Mycobacterium smegmatis

Cited by 6 publications

References 16 publications

Detecting Horizontal Gene Transfer between Closely Related Taxa

Detecting Horizontal Gene Transfer between Closely Related Taxa

Mammalian high-molecular-weight and monomeric forms of valyl-tRNA synthetase

Stimulation of valyl- and isoleucyl-tRNA synthetase reactions by polyamines

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