title: Crystal Structure Analysis of the Repair of Iron Centers Protein YtfE and Its Interaction with NO.
abstract: Molecular mechanisms underlying the repair of nitrosylated [Fe-S] clusters by the microbial protein YtfE remain poorly understood. The X-ray crystal structure of YtfE, in combination with EPR, magnetic circular dichroism (MCD), UV, and (17) O-labeling electron spin echo envelope modulation measurements, show that each iron of the oxo-bridged Fe(II) -Fe(III) diiron core is coordinatively unsaturated with each iron bound to two bridging carboxylates and two terminal histidines in addition to an oxo-bridge. Structural analysis reveals that there are two solvent-accessible tunnels, both of which converge to the diiron center and are critical for capturing substrates. The reactivity of the reduced-form Fe(II) -Fe(II) YtfE toward nitric oxide demonstrates that the prerequisite for N2 O production requires the two iron sites to be nitrosylated simultaneously. Specifically, the nitrosylation of the two iron sites prior to their reductive coupling to produce N2 O is cooperative. This result suggests that, in addition to any repair of iron centers (RIC) activity, YtfE acts as an NO-trapping scavenger to promote the NO to N2 O transformation under low NO flux, which precedes nitrosative stress.
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan.
authors.forename: Feng-Chun
authors.initials: FC
authors.lastname: Lo
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan.
authors.forename: Chang-Chih
authors.initials: CC
authors.lastname: Hsieh
authors.affiliation: Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan. mmaestre@gate.sinica.edu.tw.
authors.forename: Manuel
authors.initials: M
authors.lastname: Maestre-Reyna
authors.affiliation: Department of Life Sciences, National Central University, Taoyuan, Taiwan. chinyuchen@cc.ncu.edu.tw.
authors.forename: Chin-Yu
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
authors.forename: Tzu-Ping
authors.initials: TP
authors.lastname: Ko
authors.affiliation: Department of Chemistry, National Changhua University of Education, Changhua, Taiwan.
authors.forename: Yih-Chern
authors.initials: YC
authors.lastname: Horng
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan.
authors.forename: Yei-Chen
authors.initials: YC
authors.lastname: Lai
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan. ywchiang@mx.nthu.edu.tw.
authors.forename: Yun-Wei
authors.initials: YW
authors.lastname: Chiang
authors.affiliation: Department of Life Sciences, National Central University, Taoyuan, Taiwan.
authors.forename: Chih-Mao
authors.initials: CM
authors.lastname: Chou
authors.affiliation: National Synchrotron Radiation Research Center Hsinchu, Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Chiang
authors.affiliation: Department of Biotechnology, Yuanpei University, Hsinchu, Taiwan.
authors.forename: Wei-Ning
authors.initials: WN
authors.lastname: Huang
authors.affiliation: National Synchrotron Radiation Research Center Hsinchu, Taiwan.
authors.forename: Yi-Hung
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC, H3A2K6, Canada. scott.bohle@mcgill.ca.
authors.forename: D Scott
authors.initials: DS
authors.lastname: Bohle
authors.affiliation: Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan. wfliaw@mx.nthu.edu.tw.
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Liaw
mesh_terms: D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D007501:Iron / Q000737:chemistry*; D008667:Metalloproteins / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D009569:Nitric Oxide / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008667:Metalloproteins; D009569:Nitric Oxide; D007501:Iron
keywords: nitric oxide; non-heme diiron; protein structures; proteins