scholarly journals Axial Ligand Replacement Mechanism in Heme Transfer from Streptococcal Heme-Binding Protein Shp to HtsA of the HtsABC Transporter

Biochemistry ◽  
2013 ◽  
Vol 52 (37) ◽  
pp. 6537-6547 ◽  
Author(s):  
Yanchao Ran ◽  
G. Reza Malmirchegini ◽  
Robert T. Clubb ◽  
Benfang Lei
Keyword(s):  
Binding Protein ◽  
Axial Ligand ◽  
Heme Binding ◽  
Heme Transfer ◽  
Heme Binding Protein ◽  
Ligand Replacement

scholarly journals Ligand-induced allostery in the interaction of the Pseudomonas aeruginosa heme binding protein with heme oxygenase

2017 ◽  
Vol 114 (13) ◽  
pp. 3421-3426 ◽  
Author(s):  
Daniel J. Deredge ◽  
Weiliang Huang ◽  
Colleen Hui ◽  
Hirotoshi Matsumura ◽  
Zhi Yue ◽  
...  
Keyword(s):  
Heme Oxygenase ◽  
Binding Protein ◽  
Underlying Mechanism ◽  
Site Directed Mutagenesis ◽  
Heme Binding ◽  
Conformational Rearrangement ◽  
Terminal Domain ◽  
Heme Transfer ◽  
Hdx Ms ◽  
Heme Binding Protein

A heme-dependent conformational rearrangement of the C-terminal domain of heme binding protein (PhuS) is required for interaction with the iron-regulated heme oxygenase (HemO). Herein, we further investigate the underlying mechanism of this conformational rearrangement and its implications for heme transfer via site-directed mutagenesis, resonance Raman (RR), hydrogen–deuterium exchange MS (HDX-MS) methods, and molecular dynamics (MD). HDX-MS revealed that the apo-PhuS C-terminal α6/α7/α8-helices are largely unstructured, whereas the apo-PhuS H212R variant showed an increase in structure within these regions. The increased rate of heme association with apo-PhuS H212R compared with the WT and lack of a detectable five-coordinate high-spin (5cHS) heme intermediate are consistent with a more folded and less dynamic C-terminal domain. HDX-MS and MD of holo-PhuS indicate an overall reduction in molecular flexibility throughout the protein, with significant structural rearrangement and protection of the heme binding pocket. We observed slow cooperative unfolding/folding events within the C-terminal helices of holo-PhuS and the N-terminal α1/α2-helices that are dampened or eliminated in the holo-PhuS H212R variant. Chemical cross-linking and MALDI-TOF MS mapped these same regions to the PhuS:HemO protein–protein interface. We previously proposed that the protein–protein interaction induces conformational rearrangement, promoting a ligand switch from His-209 to His-212 and triggering heme release to HemO. The reduced conformational freedom of holo-PhuS H212R combined with the increase in entropy and decrease in heme transfer on interaction with HemO further support this model. This study provides significant insight into the role of protein dynamics in heme binding and release in bacterial heme transport proteins.

Evolution of the SOUL Heme-Binding Protein Superfamily Across Eukarya

2016 ◽  
Vol 82 (6) ◽  
pp. 279-290 ◽  
Author(s):  
Antonio Emidio Fortunato ◽  
Paolo Sordino ◽  
Nikos Andreakis
Keyword(s):  
Binding Protein ◽  
Heme Binding ◽  
Protein Superfamily ◽  
Heme Binding Protein

DHR51, theDrosophila melanogasterHomologue of the Human Photoreceptor Cell-Specific Nuclear Receptor, Is a Thiolate Heme-Binding Protein†

Biochemistry ◽  
2008 ◽  
Vol 47 (50) ◽  
pp. 13252-13260 ◽  
Author(s):  
Eve de Rosny ◽  
Arjan de Groot ◽  
Celine Jullian-Binard ◽  
Franck Borel ◽  
Cristian Suarez ◽  
...  
Keyword(s):  
Nuclear Receptor ◽  
Photoreceptor Cell ◽  
Binding Protein ◽  
Heme Binding ◽  
Heme Binding Protein
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