Disease relevance of metK

• In Escherichia coli and Salmonella typhimurium numerous studies have located a structural gene (metK) for this enzyme at 63 min on the chromosomal map [1].
• However, several strains of the typhus group rickettsiae possess metK genes lacking obvious mutations [2].
• Rapid cloning of metK encoding methionine adenosyltransferase from Corynebacterium glutamicum by screening a genomic library on a high density colony-array [3].
• As a result of harboring obligatory bacterial endosymbionts, the xD strain of Amoeba proteus no longer produces its own S-adenosylmethionine synthetase (SAMS) [4].

High impact information on metK

• S-Adenosylmethionine synthetase (ATP:l-methionine S-adenosyltransferase, MAT) catalyzes a unique enzymatic reaction that leads to formation of the primary biological alkylating agent [5].
• The bifunctional active site of S-adenosylmethionine synthetase. Roles of the basic residues [6].
• The structure of S-adenosylmethionine synthetase (MAT, ATP:L-methionine S-adenosyltransferase, EC 2.5.1.6.) from Escherichia coli has been determined at 3.0 A resolution by multiple isomorphous replacement using a uranium derivative and the selenomethionine form of the enzyme (SeMAT) [7].
• Structural and functional roles of cysteine 90 and cysteine 240 in S-adenosylmethionine synthetase [8].
• Investigation of monovalent cation activation of S-adenosylmethionine synthetase using mutagenesis and uranyl inhibition [9].

Chemical compound and disease context of metK

• Lysyl-transfer ribonucleic acid (tRNA) synthetase activity was compared in three independently isolated Escherichia coli K-12 mutants of the enzyme S-adenosyl-L-methionine synthetase (metK mutants) and their isogenic parents [10].
• Glutamyl-gamma-methyl ester acts as a methionine analogue in Escherichia coli: analogue resistant mutants map at the metJ and metK loci [11].
• Both the R. prowazekii Breinl and R. typhi Wilmington metK genes complemented at a level comparable to that of an E. coli metK control, demonstrating that the typhus group rickettsiae have the capability of synthesizing as well as transporting SAM [2].
• The enzyme S-adenosylmethionine (SAM) synthetase, the Escherichia coli metK gene product, produces SAM, the cell's major methyl donor [12].
• Previously, we reported that the problem of product inhibition of E. coli SAM synthetase encoded by the metK gene was successfully overcome in the presence of sodium p-toluenesulfonate (pTsONa) [13].

Biological context of metK

• Novel MetJ binding sites are found upstream of the metK gene, as well as upstream of a gene, abc, a gene that encodes for a component of a multifunction transporter which may transport amino acids across the membrane [14].
• The three metK mutations are recessive to the wild-type allele carried on the KLF16 episome [15].
• The DNA sequence of the Escherichia coli metK gene has been determined [16].
• Through primer extension, the transcription start site of metK was located at 140 bp upstream of the translation start site [17].
• When metK expression was limited, genomic DNA methylation decreased and cell division was hampered [17].

Associations of metK with chemical compounds

• The mutations in metK and metX are highly unstable and readily yield kanamycin-resistant cells in which the chromosomal location of the kanamycin-resistance element has changed [1].
• Mutations of the metK gene encoding S-adenosylmethionine synthetase, which is involved in Met metabolism, were detected in 12 norleucine-resistant mutants [18].
• Glycyl-L-leucine (3 mM) usually enhanced lysyl-tRNA synthetase activity two- to threefold in wild-type cells but did not further stimulate the synthetase activity in metK mutants [10].
• The SAMase-mediated hyperinduction of metH in wild-type cells and of the met genes assayed in metJ : : Tn5 and metK : : Tn5 cells provokes questions about how other elements such as the MetR activator protein or factors beyond the met regulon itself might be involved in the regulation of genes responsible for methionine biosynthesis [19].
• The sole biosynthetic route to S-adenosylmethionine, the primary biological alkylating agent, is catalysed by S-adenosylmethionine synthetase (ATP:L-methionine S-adenosyltransferase) [1].

Other interactions of metK

• Three of the mutations in the metK structural gene were then introduced into metJ and thrBC double-mutant strains; one of the resultant strains was found to accumulate 0.13 g/liter Met [18].

Analytical, diagnostic and therapeutic context of metK

• The metK transcript was detected by reverse transcription PCR in C. glutamicum cells in the exponential growth phase but not in the stationary phase [3].
• S-adenosylmethionine synthetase from Escherichia coli. Crystallization and preliminary X-ray diffraction studies [20].
• Site-directed mutagenesis of rat liver S-adenosylmethionine synthetase. Identification of a cysteine residue critical for the oligomeric state [21].

References