1lw4 | pdb_00001lw4
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X-ray structure of L-Threonine Aldolase (low-specificity) in complex with L-allo-threonine
Overview
L-Threonine acetaldehyde-lyase (threonine aldolase, TA) is a pyridoxal-5'-phosphate-dependent (PLP) enzyme that catalyzes conversion of L-threonine or L-allo-threonine to glycine and acetaldehyde in a secondary glycine biosynthetic pathway. X-ray structures of Thermatoga maritima TA have been determined as the apo-enzyme at 1.8 A resolution and bound to substrate L-allo-threonine and product glycine at 1.9 and 2.0 A resolution, respectively. Despite low pairwise sequence identities, TA is a member of aspartate aminotransferase (AATase) fold family of PLP enzymes. The enzyme forms a 222 homotetramer with the PLP cofactor bound via a Schiff-base linkage to Lys199 within a domain interface. The structure reveals bound calcium and chloride ions that appear to contribute to catalysis and oligomerization, respectively. Although L-threonine and L-allo-threonine are substrates for T. maritima TA, enzymatic assays revealed a strong preference for L-allo-threonine. Structures of the external aldimines with substrate/product reveal a pair of histidines that may provide flexibility in substrate recognition. Variation in the threonine binding pocket may explain preferences for L-allo-threonine versus L-threonine among TA family members.
About this Structure
1LW4 is a Single protein structure of sequence from Thermotoga maritima with CA, CL, TLP and PLP as ligands. Active as Threonine aldolase, with EC number 4.1.2.5 Full crystallographic information is available from OCA.
Reference
X-ray structures of threonine aldolase complexes: structural basis of substrate recognition., Kielkopf CL, Burley SK, Biochemistry. 2002 Oct 1;41(39):11711-20. PMID:12269813
Page seeded by OCA on Thu Feb 21 13:49:06 2008
Proteopedia Page Contributors and Editors (what is this?)
- Pages with broken file links
- Single protein
- Thermotoga maritima
- Threonine aldolase
- Burley, S K.
- Kielkopf, C L.
- NYSGXRC, New York Structural GenomiX Research Consortium.
- CA
- CL
- PLP
- TLP
- Enzyme
- New york structural genomix research consortium
- Nysgxrc
- Plp
- Product complex
- Protein structure initiative
- Psi
- Pyridoxal-5-phosphate
- Structural genomics
- Threonine
