1A7A: Structure Of Human Placental S-adenosylhomocysteine Hydrolase: Determination Of A 30 Selenium Atom Substructure From Data At A Single Wavelength

S-Adenosylhomocysteine (AdoHcy) hydrolase regulates all adenosylmethionine-(AdoMet) dependent transmethylations by hydrolyzing the potent feedback inhibitor AdoHcy to homocysteine and adenosine. The crystallographic structure determination of a selenomethionyl-incorporated AdoHcy hydrolase inhibitor complex was accomplished using single wavelength anomalous diffraction data and the direct methods program, Snb v2.0, which produced the positions of all 30 crystallographically distinct selenium atoms. The mode of enzyme-cofactor binding is unique, requiring interactions from two protein monomers. An unusual dual role for a catalytic water molecule in the active site is revealed in the complex with the adenosine analog 2'-hydroxy, 3'-ketocyclopent-4'-enyladenine.
PDB ID: 1A7ADownload
MMDB ID: 9935
PDB Deposition Date: 1998/3/10
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.8  Å
Source Organism:
Similar Structures:
Biological Unit for 1A7A: tetrameric; determined by author and by software (PISA,PQS)
Molecular Components in 1A7A
Label Count Molecule
Proteins (4 molecules)
S-adenosylhomocysteine Hydrolase(Gene symbol: AHCY)
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB