ISSN:
1399-0047
Source:
Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Topics:
Chemistry and Pharmacology
,
Geosciences
,
Physics
Notes:
Bovine porphobilinogen synthase (PBGS) is an homo-octameric enzyme with four active sites. Each active site binds two ZnII atoms whose ligands differ and two molecules of 5-aminolevulinate whose chemical fates differ. The asymmetric binding of two ZnII atoms and two identical substrate molecules by a homodimeric active site is apparently unique. Modification by 5-chiorolevulinate can be used to differentiate the two substrate-binding sites; diffraction-quality crystals of 5-chlorolevulinate-modified PBGS have been obtained. PbII can be used to differentiate the two different ZnII-binding sites; diffraction-quality crystals of the PbII complex of PBGS have been obtained. Preliminary diffraction data reveal an I422 space group, in agreement with a general model for the quaternary structure of PBGS.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1107/S0907444995013163
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