The ncgl1108 (PhePCg) gene encodes a new l-Phe transporter in Corynebacterium glutamicum

Applied Microbial and Cell Physiology

DOI: 10.1007/s00253-011-3245-z

Cite this article as:
Zhao, Z., Ding, JY., Li, T. et al. Appl Microbiol Biotechnol (2011) 90: 2005. doi:10.1007/s00253-011-3245-z

Abstract

Corynebacterium glutamicum played a central role in the establishment of fermentative production of amino acids, and it is a model for genetic and physiological studies. The general aromatic amino acid transporter, AroPCg, was the sole functionally identified aromatic amino acid transporter from C. glutamicum. In this study, the ncgl1108 (named as phePCg), which is located upstream of the genetic cluster (ncgl1110 ∼ ncgl1113) for resorcinol catabolism, was identified as a new l-Phe specific transporter from C. glutamicum RES167. The disruption of phePCg resulted in RES167∆ncgl1108, and this mutant showed decreased growth on l-Phe (as nitrogen source) but not on l-Tyr or l-Trp. Uptake assays with unlabeled and 14C-labeled l-Phe and l-Tyr indicated that the mutants RES167∆ncgl1108 showed significant reduction in l-Phe uptake than RES167. Expression of phePCg in RES167∆ncgl1108/pGXKZ1 or RES167∆(ncgl1108-aroPCg)/pGXKZ1 restored their ability to uptake for l-Phe and growth on l-Phe. The uptake of l-Phe was not inhibited by nine amino acids but by l-Tyr. The Km and Vmax values of RES167∆(ncgl1108-aroPCg)/pGXKZ1 for l-Phe were determined to be 10.4 ± 1.5 μM and 1.2 ± 0.1 nmol min−1 (mg DW)−1, respectively, which are different from Km and Vmax values of RES167∆(ncgl1108-aroPCg) for l-Phe [4.0 ± 0.4 μM and 0.6 ± 0.1 nmol min−1 (mg DW)−1]. In conclusion, this PhePCg is a new l-Phe transporter in C. glutamicum.

Keywords

Aromatic amino acid transporter Corynebacterium glutamicum PhePCg AroPCg l-Phenylalanine 

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of SciencesBeijingPeople’s Republic of China
  2. 2.Department of Industrial Microbiology and Biotechnology, Institute of Microbiology, Chinese Academy of SciencesBeijingPeople’s Republic of China
  3. 3.Key Laboratory of Agricultural and Environmental Microbiology, Wuhan Institute of VirologyChinese Academy of SciencesWuhanPeople’s Republic of China
  4. 4.Institute of Microbiology, Chinese Academy of SciencesBeijingPeople’s Republic of China

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