4OHR

Crystal structure of MilB from Streptomyces rimofaciens


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.184 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure of the N-glycosidase MilB in complex with hydroxymethyl CMP reveals its Arg23 specifically recognizes the substrate and controls its entry

Zhao, G.Wu, G.Zhang, Y.Liu, G.Han, T.Deng, Z.He, X.

(2014) Nucleic Acids Res 42: 8115-8124

  • DOI: 10.1093/nar/gku486
  • Primary Citation of Related Structures:  
    4OHB, 4OHR

  • PubMed Abstract: 
  • 5-Hydroxymethylcytosine (5hmC) is present in T-even phage and mammalian DNA as well as some nucleoside antibiotics, including mildiomycin and bacimethrin, during whose synthesis 5hmC is produced by the hydrolysis of 5-hydroxymethyl cytidine 5'-monophosphate (hmCMP) by an N-glycosidase MilB ...

    5-Hydroxymethylcytosine (5hmC) is present in T-even phage and mammalian DNA as well as some nucleoside antibiotics, including mildiomycin and bacimethrin, during whose synthesis 5hmC is produced by the hydrolysis of 5-hydroxymethyl cytidine 5'-monophosphate (hmCMP) by an N-glycosidase MilB. Recently, the MilB-CMP complex structure revealed its substrate specificity for CMP over dCMP. However, hmCMP instead of CMP is the preferred substrate for MilB as supported by that its KM for CMP is ∼27-fold higher than that for hmCMP. Here, we determined the crystal structures of MilB and its catalytically inactive E103A mutant in complex with hmCMP. In the structure of the complex, Phe22 and Arg23 are positioned in a cage-like active site resembling the binding pocket for the flipped 5-methylcytosine (5mC) in eukaryotic 5mC-binding proteins. Van der Waals interaction between the benzene ring of Phe22 and the pyrimidine ring of hmCMP stabilizes its binding. Remarkably, upon hmCMP binding, the guanidinium group of Arg23 was bent ∼65° toward hmCMP to recognize its 5-hydroxymethyl group, inducing semi-closure of the cage-like pocket. Mutagenesis studies of Arg23 and bioinformatics analysis demonstrate that the positively charged Arg/Lys at this site is critical for the specific recognition of the 5-hydroxymethyl group of hmCMP.


    Organizational Affiliation

    State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China xyhe@sjtu.edu.cn.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CMP/hydroxymethyl CMP hydrolase A190Streptomyces rimofaciensMutation(s): 0 
Gene Names: MilB
Find proteins for B4Y381 (Streptomyces rimofaciens)
Explore B4Y381 
Go to UniProtKB:  B4Y381
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.184 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.294α = 90
b = 102β = 90
c = 81.956γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data collection

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-06-25
    Type: Initial release
  • Version 1.1: 2016-10-19
    Changes: Database references, Structure summary
  • Version 1.2: 2017-11-22
    Changes: Refinement description