Heme-sensing ChrS/ChrA system from Corynebacterium diphtheriae

2012 Fiscal Year Final Research Report

• Project/Area Number: 23770161
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Functional biochemistry
• Research Institution: The Institute of Physical and Chemical Research
• Principal Investigator: ITO Yoko 独立行政法人理化学研究所, 細胞極性統御研究チーム, 特別研究員 (60584571)
• Project Period (FY): 2011 – 2012
• Keywords: ヘムセンサー / 二成分情報伝達系 / 宿主-病原菌相互作用 / ナノディスク

Research Abstract

To infect and proliferate in the host, pathogenic bacteria preferentially acquire iron derived from host Hb using iron-acquisition systems. Corynebacterium diphtheriae, a pathogen of diphtheria, conducts iron/heme-dependent regulatory ChrS/ChrA systems. In the present study, the ChrS protein was solubilized and purified from the membranes of an Escherichia coli overproducer, and then incorporated into Nanodiscs. The reconstituted ChrS protein exhibited direct and specific heme recognition via His21 in its first transmembrane region, hemedependent autophosphorylation and phosphoryltransfer to ChrA.