View source for 7bfi


==A double-histidine mutant of HSP47 slows down client release at low pH==
<StructureSection load='7bfi' size='340' side='right'caption='[[7bfi]], [[Resolution|resolution]] 2.44&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7bfi]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Canis_lupus_familiaris Canis lupus familiaris] and [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7BFI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7BFI FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.44&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=7bfi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7bfi OCA], [https://pdbe.org/7bfi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7bfi RCSB], [https://www.ebi.ac.uk/pdbsum/7bfi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7bfi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A8I3N7V2_CANLF A0A8I3N7V2_CANLF] Binds specifically to collagen. Could be involved as a chaperone in the biosynthetic pathway of collagen.[ARBA:ARBA00025405]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Collagens play important roles in development and homeostasis in most higher organisms. In order to function, collagens require the specific chaperone HSP47 for proper folding and secretion. HSP47 is known to bind to the collagen triple helix, but the exact positions and numbers of binding sites are not clear. Here, we employed a collagen II peptide library to characterize high-affinity binding sites for HSP47. We show that many previously predicted binding sites have very low affinities due to the presence of a negatively charged amino acid in the binding motif. In contrast, large hydrophobic amino acids such as phenylalanine at certain positions in the collagen sequence increase binding strength. For further characterization, we determined two crystal structures of HSP47 bound to peptides containing phenylalanine or leucine. These structures deviate significantly from previously published ones in which different collagen sequences were used. They reveal local conformational rearrangements of HSP47 at the binding site to accommodate the large hydrophobic side chain from the middle strand of the collagen triple helix and, most surprisingly, possess an altered binding stoichiometry in the form of a 1:1 complex. This altered stoichiometry is explained by steric collisions with the second HSP47 molecule present in all structures determined thus far caused by the newly introduced large hydrophobic residue placed on the trailing strand. This exemplifies the importance of considering all three sites of homotrimeric collagen as independent interaction surfaces and may provide insight into the formation of higher oligomeric complexes at promiscuous collagen-binding sites.

Collagen's primary structure determines collagen:HSP47 complex stoichiometry.,Abraham ET, Oecal S, Morgelin M, Schmid PWN, Buchner J, Baumann U, Gebauer JM J Biol Chem. 2021 Dec;297(6):101169. doi: 10.1016/j.jbc.2021.101169. Epub 2021 , Sep 4. PMID:34487762<ref>PMID:34487762</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7bfi" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Canis lupus familiaris]]
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Baumann U]]
[[Category: Oecal S]]