Crystal Structure of phage 44RR small terminase gp16

Experimental Data Snapshot

  • Resolution: 1.81 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.189 

Starting Model: experimental
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Structure and function of the small terminase component of the DNA packaging machine in T4-like bacteriophages.

Sun, S.Gao, S.Kondabagil, K.Xiang, Y.Rossmann, M.G.Rao, V.B.

(2012) Proc Natl Acad Sci U S A 109: 817-822

  • DOI: https://doi.org/10.1073/pnas.1110224109
  • Primary Citation of Related Structures:  
    3TXQ, 3TXS

  • PubMed Abstract: 

    Tailed DNA bacteriophages assemble empty procapsids that are subsequently filled with the viral genome by means of a DNA packaging machine situated at a special fivefold vertex. The packaging machine consists of a "small terminase" and a "large terminase" component. One of the functions of the small terminase is to initiate packaging of the viral genome, whereas the large terminase is responsible for the ATP-powered translocation of DNA. The small terminase subunit has three domains, an N-terminal DNA-binding domain, a central oligomerization domain, and a C-terminal domain for interacting with the large terminase. Here we report structures of the central domain in two different oligomerization states for a small terminase from the T4 family of phages. In addition, we report biochemical studies that establish the function for each of the small terminase domains. On the basis of the structural and biochemical information, we propose a model for DNA packaging initiation.

  • Organizational Affiliation

    Department of Biological Sciences, Purdue University, 240 S. Martin Jischke Drive, West Lafayette, IN 47907-2032, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Terminase DNA packaging enzyme small subunit
A, B, C, D
94Biquartavirus 44RR2Mutation(s): 0 
Gene Names: 16gene 16
Find proteins for Q6U9F0 (Aeromonas phage 44RR2.8t)
Explore Q6U9F0 
Go to UniProtKB:  Q6U9F0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ6U9F0
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.81 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.187 
  • R-Value Observed: 0.189 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 140.605α = 90
b = 140.605β = 90
c = 53.639γ = 120
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-12-28
    Type: Initial release
  • Version 1.1: 2012-01-25
    Changes: Database references
  • Version 1.2: 2012-02-22
    Changes: Database references
  • Version 1.3: 2023-09-13
    Changes: Data collection, Database references, Refinement description