Structure of PDB 3iwm Chain B

Receptor sequence

>3iwmB (length=301)

SGFRKMAFPSGKVEGCMVQVTCGTTTLNGLWLDDTVYCPRHVICTAEDML
NPNYEDLLIRKSNHSFLVQAGNVQLRVIGHSMQNCLLRLKVDTSNPKTPK
YKFVRIQPGQTFSVLACYNGSPSGVYQCAMRPNHTIKGSFLNGSCGSVGF
NIDYDCVSFCYMHHMELPTGVHAGTDLEGKFYGPFVDRQTAQAAGTDTTI
TLNVLAWLYAAVINGDRWFLNRFTTTLNDFNLVAMKYNYEPLTQDHVDIL
GPLSAQTGIAVLDMCAALKELLQNGMNGRTILGSTILEDEFTPFDVVRQC
S

3D structure

• PDB: 3iwm Three-dimensional domain swapping as a mechanism to lock the active conformation in a super-active octamer of SARS-CoV main protease
• Chain: B
• Resolution: 3.2 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): H41 G143 C145
• Catalytic site (residue number reindexed from 1): H41 G143 C145
• Enzyme Commision number: 2.1.1.-
  2.1.1.56: mRNA (guanine-N(7))-methyltransferase.
  2.1.1.57: methyltransferase cap1.
  2.7.7.48: RNA-directed RNA polymerase.
  2.7.7.50: mRNA guanylyltransferase.
  3.1.13.-
  3.4.19.12: ubiquitinyl hydrolase 1.
  3.4.22.-
  3.4.22.69: SARS coronavirus main proteinase.
  3.6.4.12: DNA helicase.
  3.6.4.13: RNA helicase.
  4.6.1.-

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	peptide	B	H41 N142 C145 H163 H164 M165 E166 Q189 T190 Q192	H41 N142 C145 H163 H164 M165 E166 Q189 T190 Q192
BS02	peptide	B	T25 G143	T25 G143

Gene Ontology

Molecular Function

• GO:0008233 peptidase activity

Biological Process

• GO:0019082 viral protein processing

External links

• PDB: RCSB:3iwm, PDBe:3iwm, PDBj:3iwm
• PDBsum: 3iwm
• PubMed: 21203949
• UniProt: P0C6X7|R1AB_SARS Replicase polyprotein 1ab (Gene Name=rep)