PDBsum entry 3ebn

Hydrolase

PDB id: 3ebn

Contents

Protein chains

100 a.a. *

Waters ×59

* Residue conservation analysis

PDB id:

3ebn

Name:

Hydrolase

Title:

A special dimerization of sars-cov main proteasE C-terminal domain due to domain-swapping

Structure:

Replicase polyprotein 1ab. Chain: a, b, c, d. Fragment: unp residues 3429-3546. Synonym: pp1ab, orf1ab polyprotein, 3c-like proteinase, 3cl-pro, 3clp, nsp5. Engineered: yes

Source:

Sars coronavirus. Sars-cov. Organism_taxid: 227859. Gene: rep, 1a-1b. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.40Å R-factor: 0.208 R-free: 0.243

Authors:

N.Zhong,S.Zhang,F.Xue,X.Kang,Z.Lou,B.Xia

Key ref:

N.Zhong et al. (2009). C-terminal domain of SARS-CoV main protease can form a 3D domain-swapped dimer. Protein Sci, 18, 839-844. PubMed id: 19319935

Date:

28-Aug-08 Release date: 19-May-09

Protein chains

P0C6X7  (R1AB_CVHSA) -  Replicase polyprotein 1ab from Severe acute respiratory syndrome coronavirus

Seq: 7073 a.a.

Struc: 100 a.a.

Enzyme reactions

• Enzyme class 2: E.C.2.1.1.- - ?????
• Enzyme class 3: E.C.2.1.1.56 - mRNA (guanine-N(7))-methyltransferase.
• Reaction: a 5'-end (5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L- methionine = a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-homocysteine
• Enzyme class 4: E.C.2.1.1.57 - methyltransferase cap1.
• Reaction: a 5'-end (N(7)-methyl 5'-triphosphoguanosine)-ribonucleoside in mRNA + S-adenosyl-L-methionine = a 5'-end (N(7)-methyl 5'-triphosphoguanosine)- (2'-O-methyl-ribonucleoside) in mRNA + S-adenosyl-L-homocysteine + H⁺
• Enzyme class 5: E.C.2.7.7.48 - RNA-directed Rna polymerase.
• Reaction: RNA(n) + a ribonucleoside 5'-triphosphate = RNA(n+1) + diphosphate
• Enzyme class 6: E.C.2.7.7.50 - mRNA guanylyltransferase.
• Reaction: a 5'-end diphospho-ribonucleoside in mRNA + GTP + H⁺ = a 5'-end (5'-triphosphoguanosine)-ribonucleoside in mRNA + diphosphate
• Enzyme class 7: E.C.3.1.13.- - ?????
• Enzyme class 8: E.C.3.4.19.12 - ubiquitinyl hydrolase 1.
• Reaction: Thiol-dependent hydrolysis of ester, thiolester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
• Enzyme class 9: E.C.3.4.22.- - ?????
• Enzyme class 10: E.C.3.4.22.69 - Sars coronavirus main proteinase.
• Enzyme class 11: E.C.3.6.4.12 - Dna helicase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺
• Enzyme class 12: E.C.3.6.4.13 - Rna helicase.
• Reaction: ATP + H2O = ADP + phosphate + H⁺
• Enzyme class 13: E.C.4.6.1.- - ?????

Note, where more than one E.C. class is given (as above), each may correspond to a different protein domain or, in the case of polyprotein precursors, to a different mature protein.

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

Protein Sci 18:839-844 (2009)

PubMed id: 19319935

C-terminal domain of SARS-CoV main protease can form a 3D domain-swapped dimer.

N.Zhong, S.Zhang, F.Xue, X.Kang, P.Zou, J.Chen, C.Liang, Z.Rao, C.Jin, Z.Lou, B.Xia.

ABSTRACT

SARS coronavirus main protease (M(pro)) plays an essential role in the extensive proteolytic processing of the viral polyproteins (pp1a and pp1ab), and it is an important target for anti-SARS drug development. We have reported that both the M(pro) C-terminal domain alone (M(pro)-C) and the N-finger deletion mutant of M(pro) (M(pro)-Delta7) exist as a stable dimer and a stable monomer (Zhong et al., J Virol 2008; 82:4227-4234). Here, we report structures of both M(pro)-C monomer and dimer. The structure of the M(pro)-C monomer is almost identical to that of the C-terminal domain in the crystal structure of M(pro). Interestingly, the M(pro)-C dimer structure is characterized by 3D domain-swapping, in which the first helices of the two protomers are interchanged and each is enwrapped by four other helices from the other protomer. Each folding subunit of the M(pro)-C domain-swapped dimer still has the same general fold as that of the M(pro)-C monomer. This special dimerization elucidates the structural basis for the observation that there is no exchange between monomeric and dimeric forms of M(pro)-C and M(pro)-Delta7.