Skip NavigationSkip to Content
Return Return to Search Results

Unusual conformational changes in 6-hydroxymethyl-7,8- dihydropterin pyrophosphokinase as revealed by X-ray crystallography and NMR

  1. Author:
    Xiao, B.
    Shi, G. B.
    Gao, J. H.
    Blaszczyk, J.
    Liu, Q.
    Ji, X. H.
    Yan, H. G.

  2. Author Address

    NCI, Macromol Crystallog Lab, NIH, Frederick, MD 21702 USA. NCI, Macromol Crystallog Lab, NIH, Frederick, MD 21702 USA. Michigan State Univ, Dept Biochem, E Lansing, MI 48824 USA. Ji XH NCI, Macromol Crystallog Lab, NIH, Frederick, MD 21702 USA.
    1. Year: 2001
  2. Journal: Journal of Biological Chemistry
    1. 276
    2. 43
    3. Pages: 40274-40281
  4. Type of Article: Article
  1. Abstract:

    The crystal structure of Escherichia coli 6-hydroxy-methyl-7,8- dihydropterin pyrophosphokinase (HPPK) in complex with MgADP has been determined at 1.5-Angstrom resolution with a crystallographic R factor of 0.191. The solution structure of HPPK in complex with Mg2+ and beta,gamma -methyleneadenosine 5'-triphosphate (MgAMPPCP) has been determined using a simulated annealing pro. tocol with 3,523 experimental NMR restraints. The root mean square deviation of the ensemble of 20 refined conformers that represent the solution structure from the mean coordinate set derived from them is 0.74 +/- 0.26 A for all backbone atoms and 0.49 +/- 0.22 Angstrom when residues Pro(14), Pro(44)-Gln(50), and Arg(84)-Pro(91) are excluded. Binding of MgADP causes significant changes in the conformation and dynamical property of three loops of HPPK that are involved in catalysis. A dramatic, unusual conformational change is that loop 3 moves away from the active center significantly with some residues moving by > 17 Angstrom. The binding of MgADP also stabilizes loop 1 and loop 3 but makes loop 2 more mobile. Very similar conformational and dynamical changes are observed in the NAM solution structure of HPPK(.)MgAMPPCP. The conformational and dynamical changes may play important roles in both substrate binding and product release in the catalytic cycle.

    See More

  1. Keywords:

External Sources

  1. No sources found.

Library Notes

  1. No notes added.
NCI at Frederick

You are leaving a government website.

This external link provides additional information that is consistent with the intended purpose of this site. The government cannot attest to the accuracy of a non-federal site.

Linking to a non-federal site does not constitute an endorsement by this institution or any of its employees of the sponsors or the information and products presented on the site. You will be subject to the destination site's privacy policy when you follow the link.

ContinueCancel