Structural characterization of heme environmental mutants of CgHmuT that shuttles heme molecules to heme transporters

Norifumi Muraki, Chihiro Kitatsuji, Mariko Ogura, Takeshi Uchida, Koichiro Ishimori, Shigetoshi Aono

研究成果: Article査読

8 被引用数 (Scopus)

抄録

Corynebacteria contain a heme uptake system encoded in hmuTUV genes, in which HmuT protein acts as a heme binding protein to transport heme to the cognate transporter HmuUV. The crystal structure of HmuT from Corynebacterium glutamicum (CgHmuT) reveals that heme is accommodated in the central cleft with His141 and Tyr240 as the axial ligands and that Tyr240 forms a hydrogen bond with Arg242. In this work, the crystal structures of H141A, Y240A, and R242A mutants were determined to understand the role of these residues for the heme binding of CgHmuT. Overall and heme environmental structures of these mutants were similar to those of the wild type, suggesting that there is little conformational change in the heme-binding cleft during heme transport reaction with binding and the dissociation of heme. A loss of one axial ligand or the hydrogen bonding interaction with Tyr240 resulted in an increase in the redox potential of the heme for CgHmuT to be reduced by dithionite, though the wild type was not reduced under physiological conditions. These results suggest that the heme environmental structure stabilizes the ferric heme binding in CgHmuT, which will be responsible for efficient heme uptake under aerobic conditions where Corynebacteria grow.

本文言語English
論文番号829
ジャーナルInternational journal of molecular sciences
17
6
DOI
出版ステータスPublished - 2016 6月
外部発表はい

ASJC Scopus subject areas

  • 触媒
  • 分子生物学
  • 分光学
  • コンピュータ サイエンスの応用
  • 物理化学および理論化学
  • 有機化学
  • 無機化学

フィンガープリント

「Structural characterization of heme environmental mutants of CgHmuT that shuttles heme molecules to heme transporters」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル