PDBsum entry 3frp

Hydrolase cofactor

PDB id: 3frp

Contents

Protein chains

602 a.a. *

215 a.a. *

343 a.a. *

Metals

_CA

Waters ×80

* Residue conservation analysis

PDB id:

3frp

Name:

Hydrolase cofactor

Title:

Crystal structure of cobra venom factor, a co-factor for c3- and c5 convertase cvfbb

Structure:

Cobra venom factor alpha chain. Chain: a. Synonym: cvf, complement c3 homolog, cobra venom factor alpha chain, cobra venom factor gamma chain, cobra venom factor beta chain. Cobra venom factor gamma chain. Chain: g. Synonym: cvf, complement c3 homolog, cobra venom factor alpha chain, cobra venom factor gamma chain, cobra venom factor beta chain. Cobra venom factor beta chain.

Source:

Naja kaouthia. Monocled cobra. Organism_taxid: 8649. Secretion: venom. Secretion: venom

Resolution:

2.61Å R-factor: 0.251 R-free: 0.297

Authors:

V.Krishnan,S.V.L.Narayana

Key ref:

V.Krishnan et al. (2009). The Crystal Structure of Cobra Venom Factor, a Cofactor for C3- and C5-Convertase CVFBb. Structure, 17, 611-619. PubMed id: 19368894 DOI: 10.1016/j.str.2009.01.015

Date:

08-Jan-09 Release date: 28-Apr-09

Protein chain

Q91132  (VCO3_NAJKA) -  Cobra venom factor from Naja kaouthia

Seq: 1642 a.a.

Struc: 602 a.a.

Protein chain

Q91132  (VCO3_NAJKA) -  Cobra venom factor from Naja kaouthia

Seq: 1642 a.a.

Struc: 215 a.a.

Protein chain

Q91132  (VCO3_NAJKA) -  Cobra venom factor from Naja kaouthia

Seq: 1642 a.a.

Struc: 343 a.a.

DOI no: 10.1016/j.str.2009.01.015

Structure 17:611-619 (2009)

PubMed id: 19368894

The Crystal Structure of Cobra Venom Factor, a Cofactor for C3- and C5-Convertase CVFBb.

V.Krishnan, K.Ponnuraj, Y.Xu, K.Macon, J.E.Volanakis, S.V.Narayana.

ABSTRACT

Cobra venom factor (CVF) is a functional analog of human complement component C3b, the active fragment of C3. Similar to C3b, in human and mammalian serum, CVF binds factor B, which is then cleaved by factor D, giving rise to the CVFBb complex that targets the same scissile bond in C3 as the authentic complement convertases C4bC2a and C3bBb. Unlike the latter, CVFBb is a stable complex and an efficient C5 convertase. We solved the crystal structure of CVF, isolated from Naja naja kouthia venom, at 2.6 A resolution. The CVF crystal structure, an intermediate between C3b and C3c, lacks the TED domain and has the CUB domain in an identical position to that seen in C3b. The similarly positioned CUB and slightly displaced C345c domains of CVF could play a vital role in the formation of C3 convertases by providing important primary binding sites for factor B.

Selected figure(s)

Figure 3.
Figure 3. Comparison of CVF with C3c and C3b Structures
(A) Ribbon diagrams of C3c (left), CVF (middle), and C3b (right). C3c and C3b are made of two chains, β (green) and α (red), whereas CVF is composed of three chains, α (yellow), β (magenta), and γ (cyan).
(B) Schematic depiction of domain organizations of C3c, CVF, and C3b (colored according to chains as in the ribbon in (A).

Figure 5.
Figure 5. Proposed Factor B Binding Sites
These sites are indicated (in gold) on the structure of CVF (only the top half of the molecule is shown). The small panel depicts the CVF site α'NT (gold) in comparison with the corresponding sites of C3b (green) and C3c (red).

The above figures are reprinted by permission from Cell Press: Structure (2009, 17, 611-619) copyright 2009.

Figures were selected by an automated process.