4pqc

<StructureSection load='4pqc' size='340' side='right' caption='[[4pqc]], [[Resolution|resolution]] 1.50&Aring;' scene=''>

<table><tr><td colspan='2'>[[4pqc]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4PQC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4PQC FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4it8|4it8]], [[4pqb|4pqb]], [[4pq6|4pq6]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4pqc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4pqc OCA], [http://pdbe.org/4pqc PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4pqc RCSB], [http://www.ebi.ac.uk/pdbsum/4pqc PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4pqc ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/MYG_PHYCD MYG_PHYCD]] Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles.

Heme coordination state determines the functional diversity of heme proteins. Using myoglobin as a model protein, we designed a distal hydrogen-bonding network by introducing both distal glutamic acid (Glu29) and histidine (His43) residues and regulated the heme into a bis-His coordination state with native ligands His64 and His93. This resembles the heme site in natural bis-His coordinated heme proteins such as cytoglobin and neuroglobin. A single mutation of L29E or F43H was found to form a distinct hydrogen-bonding network involving distal water molecules, instead of the bis-His heme coordination, which highlights the importance of the combination of multiple hydrogen-bonding interactions to regulate the heme coordination state. Kinetic studies further revealed that direct coordination of distal His64 to the heme iron negatively regulates fluoride binding and hydrogen peroxide activation by competing with the exogenous ligands. The new approach developed in this study can be generally applicable for fine-tuning the structure and function of heme proteins.

 

== References ==

[[Category: Wei, L]]

[[Category: Xiang-shi, T]]

[[Category: Ying-wu, L]]

[[Category: Alpha helix bundle]]

[[Category: Enzyme function initiative]]

[[Category: Structural genomic]]