Sandbox Reserved 1121: Difference between revisions

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=== CRP structure ===

The crystal structure of CRP was determined by using SAP as the search model <ref name="Thompson"/>. The structure of CRP has been ~~determined~~ by X-ray crystallography at 3 Å resolution. Like SAP, the protein consists of five protomers, uncovalently bonded and nonglycosylated that are arranged symmetrically around a central pore <ref name="Volanakis">PMID: 11532280</ref>. Each subunit is a 25 kDa protein consisting of 224 residues <ref name="uniprot">[http://www.uniprot.org/uniprot/P02741 UniProtKB - P02741 (CRP_HUMAN)]</ref>. The diameter of the CRP pentamer is 102 Å, the inner pore diameter is 30 Å and the diameter of a subunit is 36 Å <ref name="agrawal">PMID: 19799114 </ref><ref name="Volanakis"/>.Ser53, His95, Cys97, Asp112, Gly113, Gly136, Gly154, Val165, Leu166, Ile171, and Gly196 are the ~~highly~~ conserved residues in the primary sequence of CRP <ref name="kumar"/>.

The crystal structure of CRP was determined by using SAP as the search model <ref name="Thompson"/>. The structure of CRP has been obtained by X-ray crystallography at 3 Å resolution. Like SAP, the protein consists of five protomers, uncovalently bonded and nonglycosylated that are arranged symmetrically around a central pore <ref name="Volanakis">PMID: 11532280</ref>. Each subunit is a 25 kDa protein consisting of 224 residues <ref name="uniprot">[http://www.uniprot.org/uniprot/P02741 UniProtKB - P02741 (CRP_HUMAN)]</ref>. The diameter of the CRP pentamer is 102 Å, the inner pore diameter is 30 Å and the diameter of a subunit is 36 Å <ref name="agrawal">PMID: 19799114 </ref><ref name="Volanakis"/>. Ser53, His95, Cys97, Asp112, Gly113, Gly136, Gly154, Val165, Leu166, Ile171, and Gly196 are the highliest conserved residues in the primary sequence of CRP <ref name="kumar"/>.

Each subunit consist of two antiparallel <scene name='71/719862/Sheet/1'>β-sheets</scene> <ref name="uniprot"/> with a flattened jellyroll topology <ref name="Volanakis"/> and a long <scene name='71/719862/Helix/1'>α-helix</scene> (residues 168-176) lies folded against the β-sheets. The predominant structure is β-sheet <ref>PMID: 1382589</ref> but short helical regions can be noticed for the residues 43 and 185 <ref name="kumar"/>. The carboxyl terminal end of the helix along with loop 177-182 form one of the two sides of a cleft that extends from the centre of the promoter to its edge at the central pore of the pentamer <ref name="Volanakis"/>. The other side of the cleft is formed by parts of the amino and carboxyl termini of the promoter <ref name="Volanakis"/>. This furrow is 24 Å long, 7.5 Å deep and 12.4 Å wide. The side walls are constructed from Ser5, Arg6, Gln203, Pro206, Trp187, Arg188, Asn160, Gly177, Leu176, Tyr175, His95 and Asp112 <ref name="Thompson"/>. This cleft is involved in C1q binding and perhaps also with the FcR binding <ref name="Volanakis"/>.<ref name="duclos">PMID: 15531769 </ref><ref name="Volanakis"/>.The outer part of the furrow is positively charged but the inner part terminates halfway through the pentamer pore at residue Asp112, providing a ring of negative charges lining the pore <ref name="Thompson"/>. Asp112 seems to be an important residue for recognition of Cq1 by CRP <ref name="Thompson"/> because it is considered, with Tyr175, to be C1q contact residues <ref name="Volanakis"/>. Glu88 seems to influence the conformational change of C1q necessary for complement activation, while Asn158 and His38 may contribute to the correct geometry of the binding site <ref name="Volanakis"/>.

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 === CRP structure ===
-The crystal structure of CRP was determined by using SAP as the search model  <ref name="Thompson"/>. The structure of CRP has been determined by X-ray crystallography at 3 Å resolution. Like SAP, the protein consists of five protomers, uncovalently bonded and nonglycosylated that are arranged symmetrically around a central pore <ref name="Volanakis">PMID: 11532280</ref>. Each subunit is a 25 kDa protein consisting of 224 residues  <ref name="uniprot">[http://www.uniprot.org/uniprot/P02741 UniProtKB - P02741 (CRP_HUMAN)]</ref>. The diameter of the CRP pentamer is 102 Å, the inner pore diameter is 30 Å and the diameter of a subunit is 36 Å <ref name="agrawal">PMID: 19799114 </ref><ref name="Volanakis"/>.Ser53, His95, Cys97, Asp112, Gly113, Gly136, Gly154, Val165, Leu166, Ile171, and Gly196 are the highly conserved residues in the primary sequence of CRP <ref name="kumar"/>.
+The crystal structure of CRP was determined by using SAP as the search model  <ref name="Thompson"/>. The structure of CRP has been obtained by X-ray crystallography at 3 Å resolution. Like SAP, the protein consists of five protomers, uncovalently bonded and nonglycosylated that are arranged symmetrically around a central pore <ref name="Volanakis">PMID: 11532280</ref>. Each subunit is a 25 kDa protein consisting of 224 residues  <ref name="uniprot">[http://www.uniprot.org/uniprot/P02741 UniProtKB - P02741 (CRP_HUMAN)]</ref>. The diameter of the CRP pentamer is 102 Å, the inner pore diameter is 30 Å and the diameter of a subunit is 36 Å <ref name="agrawal">PMID: 19799114 </ref><ref name="Volanakis"/>. Ser53, His95, Cys97, Asp112, Gly113, Gly136, Gly154, Val165, Leu166, Ile171, and Gly196 are the highliest conserved residues in the primary sequence of CRP <ref name="kumar"/>.
 Each subunit consist of two antiparallel <scene name='71/719862/Sheet/1'>β-sheets</scene> <ref name="uniprot"/> with a flattened jellyroll topology <ref name="Volanakis"/> and a long <scene name='71/719862/Helix/1'>α-helix</scene> (residues 168-176) lies folded against the β-sheets. The predominant structure is β-sheet <ref>PMID: 1382589</ref> but short helical regions can be noticed for the residues 43 and 185 <ref name="kumar"/>.  The carboxyl terminal end of the helix along with loop 177-182 form one of the two sides of a cleft that extends from the centre of the promoter to its edge at the central pore of the pentamer <ref name="Volanakis"/>. The other side of the cleft is formed by parts of the amino and carboxyl termini of the promoter <ref name="Volanakis"/>. This furrow is 24 Å long, 7.5 Å deep and 12.4 Å wide. The side walls are constructed from Ser5, Arg6, Gln203, Pro206, Trp187, Arg188, Asn160, Gly177, Leu176, Tyr175, His95 and Asp112 <ref name="Thompson"/>. This cleft is involved in C1q binding and perhaps also with the FcR binding <ref name="Volanakis"/>.<ref name="duclos">PMID: 15531769 </ref><ref name="Volanakis"/>.The outer part of the furrow is positively charged but the inner part terminates halfway through the pentamer pore at residue Asp112, providing a ring of negative charges lining the pore <ref name="Thompson"/>. Asp112 seems to be an important residue for recognition of Cq1 by CRP <ref name="Thompson"/> because it is considered, with Tyr175, to be C1q contact residues <ref name="Volanakis"/>. Glu88 seems to influence the conformational change of C1q necessary for complement activation, while Asn158 and His38 may contribute to the correct geometry of the binding site <ref name="Volanakis"/>.