title: Identification and expression analysis of a gene encoding a shikimate transporter of Corynebacterium glutamicum.
abstract: Shikimate can be utilized as the sole source of carbon and energy of Corynebacterium glutamicum. Although biosynthesis and degradation of shikimate are well characterized in C. glutamicum, the transport of shikimate has hardly been studied. A mutant strain deficient in cgR_2523 loses the ability to grow on shikimate as well as to consume extracellular shikimate, indicating that the gene is involved in shikimate utilization (designated shiA). The hydropathy profile of the deduced amino acid sequence indicates that ShiA belongs to the metabolite/proton symporter family, which is a member of the major facilitator superfamily. An accumulation assay showed that the uptake of shikimate was hardly detected in the shiA-deficient strain, but was markedly enhanced in a shiA-expressing strain. These results suggested that the uptake of shikimate was mainly mediated by the shikimate transporter encoded by shiA. The level of shiA mRNA induction by shikimate was significantly decreased by the disruption of cgR_2524 (designated shiR), which is located immediately upstream of shiA and encodes a LysR-type transcriptional regulator, suggesting that ShiR acts as an activator of shiA. To our knowledge, this is the first report in Gram-positive bacteria of a shikimate transporter and its regulation.
authors.affiliation: Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kubota
authors.affiliation: Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Takemoto
authors.affiliation: Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hiraga
authors.affiliation: Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yukawa
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.|Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inui
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D026901:Membrane Transport Proteins / Q000235:genetics* / Q000378:metabolism; D012765:Shikimic Acid / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D026901:Membrane Transport Proteins; D012765:Shikimic Acid