Abstract
The nucleotide sequence of the genes encoding the high affinity, branched-chain amino acid transport systems LIV-I and LS has been determined. Seven genes are present on a 7568-base pair DNA fragment, six of which participate directly in branched-chain amino acid transport. Two periplasmic amino acid-binding proteins are encoded by the livJ (LIV-BP) and livK (LS-BP) genes. These two proteins confer specificity on the LIV-I and LS transport systems. livK is the first gene in a polycistronic message that includes four genes encoding membrane components, livHMGF. The protein products of the livHMGF genes are shared by the two systems. An analysis of the livH and livM DNA sequences suggests that they encode hydrophobic proteins capable of spanning the membrane several times. The LivG and LivF proteins are less hydrophobic, but are also tightly associated with the membrane. Both LivG and LivF contain the consensus sequence for adenine nucleotide binding observed in many other transport proteins. A deletion strain that does not express any of the liv genes was constructed. This strain was used to show that each of the membrane component genes is required for high affinity leucine transport, including two genes, livM and livF, for which no previous genetic evidence had been obtained.
Highlights
IntroductionK. Antonuccin, The nucleotide sequence of the genes encoding the high affinity, branched-chain amino acid transport systems LIV-I and LS has been determined
In this report we present the complete sequence of the six genes responsible for branched-chain amino acid transport in E. coli
Numbering begins at the first nucleotide following the termination codon of htpR, the gene located immediately adjacent to 1ivJ on the E. coli chromosome [11]
Summary
K. Antonuccin, The nucleotide sequence of the genes encoding the high affinity, branched-chain amino acid transport systems LIV-I and LS has been determined. Seven genes are present on a 7568-base pair DNA fragment, six of which participate directly in branched-chain amino acid transport. Two periplasmic amino acidbinding proteins are encoded by the lita (LIV-BP) and. These two proteins confer specificity on the LIV-I and LS transport systems. ZiuK is the first gene in a polycistronic message that includes four genes encoding membrane components, 1ivHMGF. The protein products of the 1ivHMGF genes are shared by the two systems. DNA sequences suggests that they encode hydrophobic proteins capable of spanning the membrane several times. The LivG and LivF proteins are less hydrophobic, but are tightly associated with the membrane
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.
