Abstract
The DNA sequence of the Escherichia coli metK gene has been determined. Protein sequence data for purified S-adenosylmethionine synthetase have also been obtained and confirm that metK is the structural gene for S-adenosylmethionine synthetase in E. coli. The sequence of the amino-terminal 35 residues of purified S-adenosylmethionine synthetase localizes the beginning of the coding region of the DNA. The open reading frame extends 1152 bases and codes for a 384-residue protein of Mr = 41,941. The gene is transcribed clockwise on the E. coli chromosome. The DNA region 5' to the coding region was found to contain symmetrical sequences suggestive of operator structures and homologous to sequences upstream from other met genes sharing the same regulatory mechanism.
Highlights
MATERIALS AND METHODSThe sequence of the amino-terminal region of AdoMet synthetase was determined using both 1and 5 mg of protein
The BamHI fragment of metK which extends from bases -68 to 111; @-galactosidaselevels produced by the fused gene are diminished in m e t J +, but not metJ, strains grown in media containing methionine.' Further experiments will be required to localize the regions of the sequence important for interaction with mtJ
Summary
The sequence of the amino-terminal region of AdoMet synthetase was determined using both 1and 5 mg of protein. All protein used for have been reported, and even astrain with atransposon sequencing was reduced and carboxymethylated as described by Sela insertion in metK has residual AdoMet synthetase activity (10).Since metK has recently been cloned (ll),we have determined the DNA sequence of metK and have obtained protein sequence data for several fragments of purified AdoMet synthetasein order to establish whether metK is et al (18) except that dithiothreitol wasused as reductant. The protein sequence of inserted in pK8 with respect to the bacterial chromosome is the amino terminus of purified AdoMet synthetase confirms known. The sequence of metK shows that the coding region the peptide sequence coded for by bases 4-108, as depicted in for this gene extends clockwise on the chromosome. We have found by construction of a gene fusion with the lacZ of plasmid pMC1403 (26) that thereis promoter activity associated with
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
