scholarly journals Highly malleable haem-binding site of the haemoprotein HasA permits stable accommodation of bulky tetraphenylporphycenes

RSC Advances ◽  
2019 ◽  
Vol 9 (32) ◽  
pp. 18697-18702 ◽  
Author(s):  
Erika Sakakibara ◽  
Yuma Shisaka ◽  
Hiroki Onoda ◽  
Daiki Koga ◽  
Ning Xu ◽  
...  
Keyword(s):  
Binding Site ◽  
Heme Binding ◽  
Flexible Loops

Bulky metallo-tetraphenylporphycene was successfully incorporated into haemophore HasA which have flexible loops surrounding heme-binding site.

scholarly journals The CytochromecFold Can Be Attained from a Compact Apo State by Occupancy of a Nascent Heme Binding Site

2001 ◽  
Vol 276 (49) ◽  
pp. 45813-45817 ◽  
Author(s):  
Rachel Wain ◽  
Thelma A. Pertinhez ◽  
Esther J. Tomlinson ◽  
Lin Hong ◽  
Christopher M. Dobson ◽  
...  
Keyword(s):  
Binding Site ◽  
Heme Binding ◽  
Apo State

scholarly journals Mechanistic insights into heme-mediated transcriptional regulation via a bacterial manganese-binding iron regulator, iron response regulator (Irr)

2020 ◽  
Vol 295 (32) ◽  
pp. 11316-11325
Author(s):  
Dayeon Nam ◽  
Yuki Matsumoto ◽  
Takeshi Uchida ◽  
Mark R. O'Brian ◽  
Koichiro Ishimori
Keyword(s):  
Binding Site ◽  
Fluorescence Anisotropy ◽  
Response Regulator ◽  
Binding Activity ◽  
Control Element ◽  
Heme Binding ◽  
Cluster Region ◽  
Ice Binding ◽  
Iron Response Regulator ◽  
Ice Complex

The transcription factor iron response regulator (Irr) is a key regulator of iron homeostasis in the nitrogen-fixating bacterium Bradyrhizobium japonicum. Irr acts by binding to target genes, including the iron control element (ICE), and is degraded in response to heme binding. Here, we examined this binding activity using fluorescence anisotropy with a 6-carboxyfluorescein-labeled ICE-like oligomer (FAM-ICE). In the presence of Mn2+, Irr addition increased the fluorescence anisotropy, corresponding to formation of the Irr–ICE complex. The addition of EDTA to the Irr–ICE complex reduced fluorescence anisotropy, but fluorescence was recovered after Mn2+ addition, indicating that Mn2+ binding is a prerequisite for complex formation. Binding activity toward ICE was lost upon introduction of substitutions in a His-cluster region of Irr, revealing that Mn2+ binds to this region. We observed that the His-cluster region is also the heme binding site; results from fluorescence anisotropy and electrophoretic mobility shift analyses disclosed that the addition of a half-equivalent of heme dissociates Irr from ICE, likely because of Mn2+ release due to heme binding. We hypothesized that heme binding to another heme binding site, Cys-29, would also inhibit the formation of the Irr–ICE complex because it is proximal to the ICE binding site, which was supported by the loss of ICE binding activity in a Cys-29–mutated Irr. These results indicate that Irr requires Mn2+ binding to form the Irr–ICE complex and that the addition of heme dissociates Irr from ICE by replacing Mn2+ with heme or by heme binding to Cys-29.

Oxygen diffusion near the heme binding site of horseradish peroxidase

1991 ◽  
Vol 178 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Victor Vargas ◽  
Juan E. Brunet ◽  
David M. Jameson
Keyword(s):  
Horseradish Peroxidase ◽  
Binding Site ◽  
Oxygen Diffusion ◽  
Heme Binding

scholarly journals 2P098 Heme binding site in Rhodnius prolixus α-glucosidase promoting the heme crystallization(02. Heme proteins,Poster)

2013 ◽  
Vol 53 (supplement1-2) ◽  
pp. S175
Author(s):  
Shotaro Kaku ◽  
Keisuke Nakatani ◽  
Haruto Ishikawa ◽  
Yasuhisa Mizutani
Keyword(s):  
Binding Site ◽  
Heme Proteins ◽  
Rhodnius Prolixus ◽  
Heme Binding

scholarly journals Structure-Function Analysis of the Bifunctional CcsBA Heme Exporter and CytochromecSynthetase

mBio ◽  
2018 ◽  
Vol 9 (6) ◽  
Author(s):  
Molly C. Sutherland ◽  
Nathan L. Tran ◽  
Dustin E. Tillman ◽  
Joshua M. Jarodsky ◽  
Jason Yuan ◽  
...  
Keyword(s):  
Structure Function ◽  
Binding Site ◽  
Binding Sites ◽  
Structural Model ◽  
Function Analysis ◽  
Integral Membrane Protein ◽  
Covalent Attachment ◽  
Heme Binding ◽  
Heme Transport ◽  
Heme Trafficking

ABSTRACTAlthough intracellular heme trafficking must occur for heme protein assembly, only a few heme transporters have been unequivocally discovered and nothing is known about their structure or mechanisms. Cytochromecbiogenesis in prokaryotes requires the transport of heme from inside to outside for stereospecific attachment to cytochromecvia two thioether bonds (at CXXCH). The CcsBA integral membrane protein was shown to transport and attach heme (and thus is a cytochromecsynthetase), but the structure and mechanisms underlying these two activities are poorly understood. We employed a new cysteine/heme crosslinking tool that traps endogenous heme in heme binding sites. We combined these data with a comprehensive imidazole correction approach (for heme ligand interrogation) to map heme binding sites. Results illuminate the process of heme transfer through the membrane to an external binding site (called the WWD domain). Using meta-genomic data (GREMLIN) and Rosetta modeling programs, a structural model of the transmembrane (TM) regions in CcsBA were determined. The heme mapping data were then incorporated to model the TM heme binding site (with TM-His1 and TM-His2 as ligands) and the external heme binding WWD domain (with P-His1 and P-His2 as ligands). Other periplasmic structure/function studies facilitated modeling of the full CcsBA protein as a framework for understanding the mechanisms. Mechanisms are proposed for heme transport from TM-His to WWD/P-His and subsequent stereospecific attachment of heme. A ligand exchange of the P-His1 for histidine of CXXCH at the synthetase active site is suggested.IMPORTANCEThe movement or trafficking of heme is critical for cellular functions (e.g., oxygen transport and energy production); however, intracellular heme is tightly regulated due to its inherent cytotoxicity. These factors, combined with the transient nature of transport, have resulted in a lack of direct knowledge on the mechanisms of heme binding and trafficking. Here, we used the cytochromecbiogenesis system II pathway as a model to study heme trafficking. System II is composed of two integral membrane proteins (CcsBA) which function to transport heme across the membrane and stereospecifically position it for covalent attachment to apocytochromec. We mapped two heme binding domains in CcsBA and suggest a path for heme trafficking. These data, in combination with metagenomic coevolution data, are used to determine a structural model of CcsBA, leading to increased understanding of the mechanisms for heme transport and the cytochromecsynthetase function of CcsBA.

Interaction of heme with a synthetic peptide mimicking the putative heme-binding site of histidine-rich glycoprotein

1987 ◽  
Vol 149 (3) ◽  
pp. 1070-1076 ◽  
Author(s):  
Masanao Katagiri ◽  
Ken Tsutsui ◽  
Toshio Yamano ◽  
Yasutsugu Shimonishi ◽  
Fumihide Ishibashi
Keyword(s):  
Binding Site ◽  
Synthetic Peptide ◽  
Heme Binding

Design of a Functional Membrane Protein by Engineering a Heme-Binding Site in Glycophorin A

2007 ◽  
Vol 129 (3) ◽  
pp. 512-518 ◽  
Author(s):  
Jeanine M. Cordova ◽  
Pamela L. Noack ◽  
Simon A. Hilcove ◽  
James D. Lear ◽  
Giovanna Ghirlanda
Keyword(s):  
Membrane Protein ◽  
Binding Site ◽  
Glycophorin A ◽  
Heme Binding ◽  
Functional Membrane
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