2H9C

Native Crystal Structure of the Isochorismate-Pyruvate Lyase from Pseudomonas aeruginosa

Summary for 2H9C

• Entry DOI: 10.2210/pdb2h9c/pdb
• Related: 2h9d
• Descriptor: Salicylate biosynthesis protein pchB, NITRATE ION (3 entities in total)
• Functional Keywords: intertwinded dimer, lyase
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 2
• Total formula weight: 22919.84

Authors

Lamb, A.L.,Zaitseva, J.,Lu, J. (deposition date: 2006-06-09, release date: 2006-08-15, Last modification date: 2023-08-30)

Primary citation

Zaitseva, J.,Lu, J.,Olechoski, K.L.,Lamb, A.L.
Two Crystal Structures of the Isochorismate Pyruvate Lyase from Pseudomonas aeruginosa.
J.Biol.Chem., 281:33441-33449, 2006

PubMed Abstract: Enzymatic systems that exploit pericyclic reaction mechanisms are rare. A recent addition to this class is the enzyme PchB, an 11.4-kDa isochorismate pyruvate lyase from Pseudomonas aeruginosa. The apo and pyruvate-bound structures of PchB reveal that the enzyme is a structural homologue of chorismate mutases in the AroQalpha class despite low sequence identity (20%). The enzyme is an intertwined dimer of three helices with connecting loops, and amino acids from each monomer participate in each of two active sites. The apo structure (2.35 A resolution) has one dimer per asymmetric unit with nitrate bound in an open active site. The loop between the first and second helices is disordered, providing a gateway for substrate entry and product exit. The pyruvate-bound structure (1.95 A resolution) has two dimers per asymmetric unit. One has two open active sites like the apo structure, and the other has two closed active sites with the loop between the first and second helices ordered for catalysis. Determining the structure of PchB is part of a larger effort to elucidate protein structures involved in siderophore biosynthesis, as these enzymes are crucial for bacterial iron uptake and virulence and have been identified as antimicrobial drug targets.

PubMed: 16914555
DOI: 10.1074/jbc.M605470200

Experimental method

X-RAY DIFFRACTION (2.35 Å)