1YYP

Crystal structure of cytomegalovirus UL44 bound to C-terminal peptide from CMV UL54


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 

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This is version 1.4 of the entry. See complete history


Literature

Crystal structure of the cytomegalovirus DNA polymerase subunit UL44 in complex with the C terminus from the catalytic subunit. Differences in structure and function relative to unliganded UL44.

Appleton, B.A.Brooks, J.Loregian, A.Filman, D.J.Coen, D.M.Hogle, J.M.

(2006) J Biol Chem 281: 5224-5232

  • DOI: 10.1074/jbc.M506900200
  • Primary Citation of Related Structures:  
    1YYP

  • PubMed Abstract: 
  • The human cytomegalovirus DNA polymerase is composed of a catalytic subunit, UL54, and an accessory protein, UL44, which has a structural fold similar to that of other processivity factors, including herpes simplex virus UL42 and homotrimeric sliding clamps such as proliferating cell nuclear antigen ...

    The human cytomegalovirus DNA polymerase is composed of a catalytic subunit, UL54, and an accessory protein, UL44, which has a structural fold similar to that of other processivity factors, including herpes simplex virus UL42 and homotrimeric sliding clamps such as proliferating cell nuclear antigen. Several specific residues in the C-terminal region of UL54 and in the "connector loop" of UL44 are required for the association of these proteins. Here, we describe the crystal structure of residues 1-290 of UL44 in complex with a peptide from the extreme C terminus of UL54, which explains this interaction at a molecular level. The UL54 peptide binds to structural elements similar to those used by UL42 and the sliding clamps to associate with their respective binding partners. However, the details of the interaction differ from those of other processivity factor-peptide complexes. Crucial residues include a three-residue hydrophobic "plug" from the UL54 peptide and Ile(135) of UL44, which forms a critical intramolecular hydrophobic anchor for interactions between the connector loop and the peptide. As was the case for the unliganded UL44 structure, the UL44-peptide complex forms a head-to-head dimer that could potentially form a C-shaped clamp on DNA. However, the peptide-bound structure displays subtle differences in the relative orientation of the two subdomains of the protein, resulting in a more open clamp, which we predicted would affect its association with DNA. Indeed, filter binding assays revealed that peptide-bound UL44 binds DNA with higher affinity. Thus, interaction with the catalytic subunit appears to affect both the structure and function of UL44.


    Related Citations: 
    • The cytomegalovirus DNA polymerase subunit UL44 forms a C clamp-shaped dimer
      (2004) Mol Cell 15: 233
    • Specific residues in the connector loop of the human cytomegalovirus DNA polymerase accessory protein UL44 are crucial for interaction with the UL54 catalytic subunit
      (2004) J Virol 78: 9084
    • Residues of human cytomegalovirus DNA polymerase catalytic subunit UL54 that are necessary and sufficient for interaction with the accessory protein UL44
      (2004) J Virol 78: 158
    • Physical and functional interaction of human cytomegalovirus DNA polymerase and its accessory protein (ICP36) expressed in insect cells
      (1992) J Virol 66: 4126

    Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DNA polymerase processivity factorA290Human betaherpesvirus 5Mutation(s): 0 
Gene Names: UL44
UniProt
Find proteins for P16790 (Human cytomegalovirus (strain AD169))
Explore P16790 
Go to UniProtKB:  P16790
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP16790
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
DNA polymeraseB22N/AMutation(s): 0 
EC: 2.7.7.7
UniProt
Find proteins for P08546 (Human cytomegalovirus (strain AD169))
Explore P08546 
Go to UniProtKB:  P08546
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08546
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.197 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 91.787α = 90
b = 127.592β = 90
c = 65.975γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing
RESOLVEphasing
REFMACrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-12-27
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Refinement description, Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2018-01-24
    Changes: Structure summary