Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 61.23 kDa 
• Atom Count: 4305 
• Modelled Residue Count: 466 
• Deposited Residue Count: 520 
• Unique protein chains: 1

1G60

Crystal Structure of Methyltransferase MboIIa (Moraxella bovis)

• PDB DOI: 10.2210/pdb1G60/pdb

• Classification: TRANSFERASE
• Organism(s): Moraxella bovis
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2000-11-02 Released: 2002-05-01 
• Deposition Author(s): Osipiuk, J., Walsh, M.A., Joachimiak, A., Midwest Center for Structural Genomics (MCSG)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.74 Å
• R-Value Free: 0.221 
• R-Value Work: 0.198 
• R-Value Observed: 0.199 

Literature

Crystal structure of MboIIA methyltransferase.

Osipiuk, J., Walsh, M.A., Joachimiak, A.

(2003) Nucleic Acids Res 31: 5440-5448

• PubMed: 12954781 
• DOI: 10.1093/nar/gkg713
• Primary Citation of Related Structures:  
  1G60


• PubMed Abstract: 
  

DNA methyltransferases (MTases) are sequence-specific enzymes which transfer a methyl group from S-adenosyl-L-methionine (AdoMet) to the amino group of either cytosine or adenine within a recognized DNA sequence. Methylation of a base in a specific DNA sequence protects DNA from nucleolytic cleavage by restriction enzymes recognizing the same DNA sequence. We have determined at 1.74 A resolution the crystal structure of a beta-class DNA MTase MboIIA (M.MboIIA) from the bacterium Moraxella bovis, the smallest DNA MTase determined to date. M.MboIIA methylates the 3' adenine of the pentanucleotide sequence 5'-GAAGA-3'. The protein crystallizes with two molecules in the asymmetric unit which we propose to resemble the dimer when M.MboIIA is not bound to DNA. The overall structure of the enzyme closely resembles that of M.RsrI. However, the cofactor-binding pocket in M.MboIIA forms a closed structure which is in contrast to the open-form structures of other known MTases.

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Related Citations: 

• Cloning and Characterization of the MboII Restriction-modification System
  Bocklage, H., Heeger, K., Muller-Hill, B.
  (1991) Nucleic Acids Res 19: 1007

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Organizational Affiliation: 

Argonne National Laboratory, Biosciences Division and Structural Biology Center, 9700 South Cass Avenue, Argonne, IL 60439, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Adenine-specific Methyltransferase MboIIA	A, B	260	Moraxella bovis	Mutation(s): 0  Gene Names: mboIIM EC: 2.1.1.72
UniProt
Find proteins for P23192 (Moraxella bovis) Explore P23192  Go to UniProtKB:  P23192

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
SAM	D [auth A], F [auth B]	S-ADENOSYLMETHIONINE C15 H22 N6 O5 S MEFKEPWMEQBLKI-FCKMPRQPSA-N
NA	C [auth A], E [auth B]	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.74 Å
• R-Value Free: 0.221 
• R-Value Work: 0.198 
• R-Value Observed: 0.199 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 60.818	α = 90
b = 98.699	β = 101.93
c = 50.894	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
SCALEPACK	data scaling
CNS	refinement
REFMAC	refinement
HKL-2000	data reduction
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2000-11-02 
• Released Date: 2002-05-01 
Deposition Author(s): Osipiuk, J., Walsh, M.A., Joachimiak, A., Midwest Center for Structural Genomics (MCSG)

Revision History  

• Version 1.0: 2002-05-01
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance