PDBsum entry 3hqb

Immune system

PDB id: 3hqb

Contents

Protein chains

63 a.a. *

* Residue conservation analysis

PDB id:

3hqb

Name:

Immune system

Title:

Crystal structure of human desarg-c5a

Structure:

Complement c5. Chain: a, b. Synonym: c3 and pzp-like alpha-2-macroglobulin domain-containing protein 4, complement c5 beta chain, complement c5 alpha chain, c5a anaphylatoxin, complement c5 alpha' chain. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Gene: c5, cpamd4. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

3.30Å R-factor: 0.219 R-free: 0.307

Authors:

W.J.Cook,S.E.Ealick

Key ref:

W.J.Cook et al. (2010). Structure of human desArg-C5a. Acta Crystallogr D Biol Crystallogr, 66, 190-197. PubMed id: 20124699

Date:

05-Jun-09 Release date: 02-Feb-10

Protein chains

P01031  (CO5_HUMAN) -  Complement C5 from Homo sapiens

Seq: 1676 a.a.

Struc: 63 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Acta Crystallogr D Biol Crystallogr 66:190-197 (2010)

PubMed id: 20124699

Structure of human desArg-C5a.

W.J.Cook, N.Galakatos, W.C.Boyar, R.L.Walter, S.E.Ealick.

ABSTRACT

The anaphylatoxin C5a is derived from the complement component C5 during activation of the complement cascade. It is an important component in the pathogenesis of a number of inflammatory diseases. NMR structures of human and porcine C5a have been reported; these revealed a four-helix bundle stabilized by three disulfide bonds. The crystal structure of human desArg-C5a has now been determined in two crystal forms. Surprisingly, the protein crystallizes as a dimer and each monomer in the dimer has a three-helix core instead of the four-helix bundle noted in the NMR structure determinations. Furthermore, the N-terminal helices of the two monomers occupy different positions relative to the three-helix core and are completely different from the NMR structures. The physiological significance of these structural differences is unknown.