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Overview for MACiE Entry M0238

Version history

General Information

EC Number: 3.4.21.97 (A member of the Hydrolases, Acting on peptide bonds (peptidases), Serine endopeptidases)

Enzyme Name: assemblin

Biological Species: Human cytomegalovirus (Human cytomegalovirus)

Catalytic Chain UniprotKB Accession Codes:

Representative PDB Code: 1wpo - HYDROLYTIC ENZYME HUMAN CYTOMEGALOVIRUS PROTEASE (Resolution = 2.00 Å).

Catalytic CATH Codes:

  • 3.20.16.10 - Serine Protease, Human Cytomegalovirus Protease; Chain A

"Other" CATH Codes:

  • 3.20.16.10 - Serine Protease, Human Cytomegalovirus Protease; Chain A

Display structure information

Overall Reaction:

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Image of Water

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Image of C-terminus of a protein

Image of N-terminus of a protein

Protein
C00017
CHEBI:36080
Water
C00001
CHEBI:15377
C-terminus of a protein
X00073
CHEBI:33711
N-terminus of a protein
X00119
CHEBI:33712

Overall Comment: This enzyme is a serine protease. However it shares no sequence homology with classical serine proteases and has a Ser-His-His catalytic triad, as opposed to the classical Ser-His-Asp/Glu.


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Stepwise Description of the Reaction

Step 1His63 deprotonates Ser132, which can then act as the nucleophile for attack on the carbonyl carbon of the substrate. This forms a tetrahedral intermediate that is stabilised by the oxyanion hole.
Step 2The tetrahedral intermediate collapses and eliminates the new N-terminus of the protein, which is then protonated by His63.
Step 3His63 deprotonates water, which can then act as the nucleophile for attack on the carbonyl carbon of the acyl-enzyme. This forms a tetrahedral intermediate that is stabilised by the oxyanion hole.
Step 4The tetrahedral intermediate collapses and eliminates Ser132, which is then protonated by His63.

View similar reactions (composite manual annotation)


Catalytic Residues Involved

Type Number Chain Location of Function
Ser 132 A Side Chain
His 63 A Side Chain
His 157 A Side Chain
Ser 134 A Side Chain
Arg 165 A Main Chain Amide
Arg 166 A Side Chain

References

  1. P. H. Liang et al. (1998), Biochemistry, 37, 5923-5929. Site-directed mutagenesis probing the catalytic role of arginines 165 and 166 of human cytomegalovirus protease.
    Medline: 9558326
  2. G. A. Cox et al. (1995), J. Virol., 69, 4524-4528. Human cytomegalovirus proteinase: candidate glutamic acid identified as third member of putative active-site triad.
    Medline: 7769716
  3. P. Chen et al. (1996), Cell, 86, 835-843. Structure of the human cytomegalovirus protease catalytic domain reveals a novel serine protease fold and catalytic triad.
    Medline: 8797829
  4. R. Khayat et al. (2001), Biochemistry, 40, 6344-6351. Investigating the role of histidine 157 in the catalytic activity of human cytomegalovirus protease.
    Medline: 11371196

Homologue information for M0238 (1wpo)

CSA Homologues

MACiE Homologues (within the PDB)

MACiE Homologues (within UniprotKB/SwissProt)


Links to this entry in other databases

Link to EC-PDB-SUM Link to PDB-SUM Link to RCSB PDB Link to PDBe Link to CSA
Link to MetaCyc Link to KEGG Link to BRENDA Link to ExplorENZ

GOA logo
serine-type endopeptidase activity (molecular function)
proteolysis (biological process)
peptidase activity (molecular function)
serine-type peptidase activity (molecular function)
hydrolase activity (molecular function)
viral capsid assembly (biological process)
host cell cytoplasm (cellular component)
host cell nucleus (cellular component)
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