4zu2

Publication Abstract from PubMed

Pseudomonas aeruginosa is one of only a few Pseudomonas species that are able to use acyclic monoterpenoids such as citronellol and citronellate as carbon and energy source. This is achieved by the acyclic terpene utilization pathway (Atu) that includes at least six enzymes (AtuA, B, CF, D, E, G) and is coupled to a functional leucine-isovalerate utilization (Liu) pathway. Here, quantitative proteome analysis was performed to elucidate the terpene metabolism of P. aeruginosa. The proteomics survey identified 187 proteins, including AtuA-AtuG and LiuA-LiuE, which were increased in abundance in the presence of citronellate. In particular, two hydratases, AtuE and the PA4330 gene product, out of more that a dozen predicted in the P. aeruginosa proteome, showed an increased abundance in the presence of citronellate. AtuE (isohexenyl glutaconyl-CoA hydratase; EC 4.2.1.57) most likely catalyzes the hydration of the unsaturated distal double bond in isohexenyl-glutaconyl-CoA thioester to yield 3-hydroxy-3-isohexenyl-glutaryl-CoA. Determination of the crystal structure of AtuE at 2.13-A resolution revealed a fold similar to that found in the hydratase (crotonase) superfamily and provided insights in the nature of the active site. The AtuE active-site architecture showed a significantly broader cavity compared to other crotonase superfamily members in agreement with the need to accommodate the branched isoprenoid unit of terpenes. Glu139 was identified as potential catalytic residue while the backbone -NH groups of Gly116 and Gly68 are likely to form an oxyanion hole. The present work will deepen the understanding of terpene metabolism in Pseudomonas and may serve as a basis to develop new strategies for biotechnological production of terpenoids.

Pseudomonas aeruginosa Isohexenyl Glutaconyl-CoA Hydratase (AtuE) Is Upregulated in Citronellate-grown Cells and Belongs to the Crotonase Family.,Poudel N, Pfannstiel J, Simon O, Walter N, Papageorgiou AC, Jendrossek D Appl Environ Microbiol. 2015 Jul 10. pii: AEM.01686-15. PMID:26162879^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.