199D

Solution structure of the monoalkylated mitomycin c-DNA complex


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 
  • Conformers Submitted: 
  • Selection Criteria: all calculated structures submitted 

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This is version 1.2 of the entry. See complete history


Literature

Solution structure of the monoalkylated mitomycin C-DNA complex.

Sastry, M.Fiala, R.Lipman, R.Tomasz, M.Patel, D.J.

(1995) J Mol Biol 247: 338-359

  • DOI: 10.1006/jmbi.1994.0143
  • Primary Citation of Related Structures:  
    199D

  • PubMed Abstract: 
  • Mitomycin C (MC) is a potent antitumor antibiotic which alkylates DNA through covalent linkage of its C-1" position with the exocyclic N2 amino group of guanine to yield the [MC]dG adduct at the duplex level. We report on the solution structure of the monoalkylated MC-DNA 9-mer complex where the [MC]dG5 adduct is positioned opposite dC14 in the d(A3-C4-[MC]G5-T6) ...

    Mitomycin C (MC) is a potent antitumor antibiotic which alkylates DNA through covalent linkage of its C-1" position with the exocyclic N2 amino group of guanine to yield the [MC]dG adduct at the duplex level. We report on the solution structure of the monoalkylated MC-DNA 9-mer complex where the [MC]dG5 adduct is positioned opposite dC14 in the d(A3-C4-[MC]G5-T6).d(A13-C14-G15-T16) sequence context. The solution structure was solved based on a combined NMR-molecular dynamics study including NOE intensity based refinement. The formation of the [MC]dG adduct occurs with retention of the Watson-Crick alignment at the [MC]dG5.dC14 base-pair and flanking pairs in the complex. The MC ring is positioned in the minor groove with its indoloquinone aromatic ring system at a approximately 45 degrees angle relative to the helix axis and directed towards the 3'-direction on the unmodified strand. The MC indoloquinone chromophore is asymmetrically positioned in a slightly widened minor groove so that its plane is parallel to and stacked over the d(C14-G15-T16) segment on the unmodified strand with its other face exposed to solvent. The MC five-membered ring adopts an envelope pucker with its C-2" atom displaced from the mean plane and directed away from the unmodified strand. We observe conformational perturbations in the DNA 9-mer duplex on formation of the monoalkylated MC complex. Specifically, the base-pairs are displaced by approximately -3.0 A towards the major groove on positioning the MC in the minor groove. This perturbation is accompanied by base stacking patterns similar to those observed in A-DNA while the majority of the sugars adopt puckers characteristic of B-DNA. Conformational perturbations as monitored by helix twist, sugar pucker pseudorotation and glycosidic torsion angles are also observed for the d(T6-C7-I8).d(C11-G12-A13) segment that is adjacent to but does not overlap the MC binding on the 9-mer duplex. We note that the O-10" atom on the carbamate side-chain of MC forms an intermolecular hydrogen bond with the exocyclic amino group of dG15 in two of the three refined structures of the complex. The solution structure of the complex containing this intramolecular hydrogen bond readily explains both the previously observed d(C-G).d(C-G) sequence requirement for cross-linking and the observed, somewhat less stringent, requirement of the same sequence for the initial monoalkylation step.(ABSTRACT TRUNCATED AT 400 WORDS)


    Organizational Affiliation

    Department of Biochemistry and Molecular Biophysics, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.



Macromolecules
  • Find similar nucleic acids by:  Sequence   |   Structure
  • Entity ID: 1
    MoleculeChainsLengthOrganismImage
    DNA (5'-D(*(DI)P*CP*AP*CP*GP*TP*CP*(DI)P*T)-3')A9N/A
    Protein Feature View
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    • Reference Sequence
    • Find similar nucleic acids by:  Sequence   |   Structure
    • Entity ID: 2
      MoleculeChainsLengthOrganismImage
      DNA (5'-D(*AP*CP*GP*AP*CP*GP*TP*GP*C)-3')B9N/A
      Protein Feature View
      Expand
      • Reference Sequence
      Small Molecules
      Ligands 1 Unique
      IDChainsName / Formula / InChI Key2D Diagram3D Interactions
      MOC (Subject of Investigation/LOI)
      Query on MOC

      Download Ideal Coordinates CCD File 
      C [auth A]CARBAMIC ACID 2,6-DIAMINO-5-METHYL-4,7-DIOXO-2,3,4,7-TETRAHYDRO-1H-3A-AZA-CYCLOPENTA[A]INDEN-8-YLMETHYL ESTER
      C14 H16 N4 O4
      SMCLMIIQNWUTHU-ZCFIWIBFSA-N
       Ligand Interaction
      Experimental Data & Validation

      Experimental Data

      • Method: SOLUTION NMR
      • Conformers Calculated: 
      • Conformers Submitted: 
      • Selection Criteria: all calculated structures submitted 
      • OLDERADO: 199D Olderado

      Structure Validation

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      Entry History 

      Deposition Data

      Revision History  (Full details and data files)

      • Version 1.0: 1995-02-07
        Type: Initial release
      • Version 1.1: 2008-03-24
        Changes: Version format compliance
      • Version 1.2: 2011-07-13
        Changes: Version format compliance