3KZN

Crystal structure of N-acetyl-L-ornithine transcarbamylase complexed with N-acetyl-L-ornirthine

Replaces:  1ZQ6

Summary for 3KZN

• Entry DOI: 10.2210/pdb3kzn/pdb
• Related: 2FG7 3KZC 3KZK 3KZM 3KZO 3L02 3L04 3L05 3L06
• Descriptor: N-acetylornithine carbamoyltransferase, N~2~-ACETYL-L-ORNITHINE, GLYCEROL, ... (5 entities in total)
• Functional Keywords: transcarbamylase, amino-acid biosynthesis, arginine biosynthesis, cytoplasm, transferase
• Biological source: Xanthomonas campestris pv. campestris
• Cellular location: Cytoplasm (Probable): Q8P8J2
• Total number of polymer chains: 1
• Total formula weight: 40684.08

Authors

Shi, D.,Yu, X.,Allewell, N.M.,Tuchman, M. (deposition date: 2009-12-08, release date: 2010-03-31, Last modification date: 2023-11-22)

Primary citation

Shi, D.,Yu, X.,Roth, L.,Morizono, H.,Tuchman, M.,Allewell, N.M.
Structures of N-acetylornithine transcarbamoylase from Xanthomonas campestris complexed with substrates and substrate analogs imply mechanisms for substrate binding and catalysis.
Proteins, 64:532-542, 2006

PubMed Abstract: N-acetyl-L-ornithine transcarbamoylase (AOTCase) is a new member of the transcarbamoylase superfamily that is essential for arginine biosynthesis in several eubacteria. We report here crystal structures of the binary complexes of AOTCase with its substrates, carbamoyl phosphate (CP) or N-acetyl-L-ornithine (AORN), and the ternary complex with CP and N-acetyl-L-norvaline. Comparison of these structures demonstrates that the substrate-binding mechanism of this novel transcarbamoylase is different from those of aspartate and ornithine transcarbamoylases, both of which show ordered substrate binding with large domain movements. CP and AORN bind to AOTCase independently, and the main conformational change upon substrate binding is ordering of the 80's loop, with a small domain closure around the active site and little movement of the 240's loop. The structures of the complexes provide insight into the mode of substrate binding and the mechanism of the transcarbamoylation reaction.

PubMed: 16741992
DOI: 10.1002/prot.21013

Experimental method

X-RAY DIFFRACTION (1.8 Å)