All tetrapyrroles are synthesized through a branched pathway, and although each tetrapyrrole receives unique modifications around the ring periphery, they all share the unifying feature of a central metal ion. Each pathway maintains a unique metal ion chelatase, and several tertiary structures have been determined, including those of the protoporphyrin ferrochelatase from both human and Bacillus subtilus, and the cobalt chelatase CbiK. These enzymes exhibit strong structural similarity and appear to function by a similar mechanism. Met8p, from Saccharomyces cerevisiae, catalyses ferrochelation during the synthesis of sirohaem, and the structure reveals a novel chelatase architecture whereby both ferrochelation and NAD+-dependent dehydrogenation take place in a single bifunctional active site. Asp-141 appears to participate in both catalytic reactions. The final common biosynthetic step in tetrapyrrole biosynthesis is the generation of uroporphyrinogen by uroporphyrinogen III synthase, whereby the D ring of hydroxymethylbilane is flipped during ring closure to generate the asymmetrical structure of uroporphyrinogen III. The recently derived structure of uroporphyrinogen III synthase reveals a bi-lobed structure in which the active site lies between the domains.
Skip Nav Destination
Article navigation
August 2002
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
Conference Article|
August 01 2002
Structural diversity in metal ion chelation and the structure of uroporphyrinogen III synthase
H. L. Schubert;
H. L. Schubert
1
*Department of Biochemistry, University of Utah, Salt Lake City, UT 84132-3201, U.S.A.
1To whom correspondence should be addressed (e-mail heidi@biochem.utah.edu)
Search for other works by this author on:
E. Raux;
E. Raux
†Department of Biochemistry, Queen Mary College, London E1 4NS, U.K.
Search for other works by this author on:
M. A. A. Matthews;
M. A. A. Matthews
*Department of Biochemistry, University of Utah, Salt Lake City, UT 84132-3201, U.S.A.
Search for other works by this author on:
J. D. Phillips;
J. D. Phillips
*Department of Biochemistry, University of Utah, Salt Lake City, UT 84132-3201, U.S.A.
Search for other works by this author on:
K. S. Wilson;
K. S. Wilson
‡Structural Biology Laboratory, University of York, York YO10 5DD, U.K.
Search for other works by this author on:
C. P. Hill;
C. P. Hill
*Department of Biochemistry, University of Utah, Salt Lake City, UT 84132-3201, U.S.A.
Search for other works by this author on:
M. J. Warren
M. J. Warren
†Department of Biochemistry, Queen Mary College, London E1 4NS, U.K.
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
March 12 2002
Online ISSN: 1470-8752
Print ISSN: 0300-5127
© 2002 Biochemical Society
2002
Biochem Soc Trans (2002) 30 (4): 595–600.
Article history
Received:
March 12 2002
Citation
H. L. Schubert, E. Raux, M. A. A. Matthews, J. D. Phillips, K. S. Wilson, C. P. Hill, M. J. Warren; Structural diversity in metal ion chelation and the structure of uroporphyrinogen III synthase. Biochem Soc Trans 1 August 2002; 30 (4): 595–600. doi: https://doi.org/10.1042/bst0300595
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.