7T63

Crystal structure of a delta 6 18:0-ACP desaturase from Thunbergia laurifolia

Summary for 7T63

• Entry DOI: 10.2210/pdb7t63/pdb
• Descriptor: DESATURASE, FE (II) ION (3 entities in total)
• Functional Keywords: oxidoreductase, delta6 fatty acid desaturase, binuclear iron center, electron transfer
• Biological source: Thunbergia laurifolia
• Total number of polymer chains: 2
• Total formula weight: 79158.76

Authors

Liu, Q.,Chai, J.,Shanklin, J. (deposition date: 2021-12-13, release date: 2022-07-13, Last modification date: 2023-10-25)

Primary citation

Gan, L.,Park, K.,Chai, J.,Updike, E.M.,Kim, H.,Voshall, A.,Behera, S.,Yu, X.H.,Cai, Y.,Zhang, C.,Wilson, M.A.,Mower, J.P.,Moriyama, E.N.,Zhang, C.,Kaewsuwan, S.,Liu, Q.,Shanklin, J.,Cahoon, E.B.
Divergent evolution of extreme production of variant plant monounsaturated fatty acids.
Proc.Natl.Acad.Sci.USA, 119:e2201160119-e2201160119, 2022

PubMed Abstract: Metabolic extremes provide opportunities to understand enzymatic and metabolic plasticity and biotechnological tools for novel biomaterial production. We discovered that seed oils of many species contain up to 92% of the unusual monounsaturated petroselinic acid (18:1Δ6), one of the highest reported levels for a single fatty acid in plants. Supporting the biosynthetic origin of petroselinic acid, we identified a Δ6-stearoyl-acyl carrier protein (18:0-ACP) desaturase from , closely related to a previously identified Δ6-palmitoyl-ACP desaturase that produces sapienic acid (16:1Δ6)-rich oils in seeds. Guided by a desaturase crystal structure obtained in this study, enzyme mutagenesis identified key amino acids for functional divergence of Δ6 desaturases from the archetypal Δ9-18:0-ACP desaturase and mutations that result in nonnative enzyme regiospecificity. Furthermore, we demonstrate the utility of the desaturase for the production of unusual monounsaturated fatty acids in engineered plant and bacterial hosts. Through stepwise metabolic engineering, we provide evidence that divergent evolution of extreme petroselinic acid and sapienic acid production arises from biosynthetic and metabolic functional specialization and enhanced expression of specific enzymes to accommodate metabolism of atypical substrates.

PubMed: 35867834
DOI: 10.1073/pnas.2201160119

Experimental method

X-RAY DIFFRACTION (2 Å)