5GUC

Crystal structure of CotB2 (apo form) from Streptomyces melanosporofaciens

Summary for 5GUC

• Entry DOI: 10.2210/pdb5guc/pdb
• Related: 5GUE
• Descriptor: Cyclooctat-9-en-7-ol synthase, FORMIC ACID (3 entities in total)
• Functional Keywords: terpene cyclase fold, diterpene cyclase, lyase, biosynthetic protein
• Biological source: Streptomyces melanosporofaciens
• Total number of polymer chains: 2
• Total formula weight: 76476.31

Authors

Tomita, T.,Kim, S.-Y.,Ozaki, T.,Yoshida, A.,Kuzuyama, T.,Nishiyama, M. (deposition date: 2016-08-28, release date: 2017-06-07, Last modification date: 2024-03-20)

Primary citation

Tomita, T.,Kim, S.-Y.,Teramoto, K.,Meguro, A.,Ozaki, T.,Yoshida, A.,Motoyoshi, Y.,Mori, N.,Ishigami, K.,Watanabe, H.,Nishiyama, M.,Kuzuyama, T.
Structural Insights into the CotB2-Catalyzed Cyclization of Geranylgeranyl Diphosphate to the Diterpene Cyclooctat-9-en-7-ol
ACS Chem. Biol., 12:1621-1628, 2017

PubMed Abstract: The diterpene cyclase CotB2 catalyzes the cyclization of geranylgeranyl diphosphate (GGPP) to the tricyclic cyclooctat-9-en-7-ol, which is characterized by a 5-8-5-fused ring skeleton. We have previously proposed a cyclization cascade involving a unique carbon-carbon bond rearrangement combined with multiple hydride shifts, all occurring at a single active site. Here, we report the first high-resolution X-ray crystal structure of CotB2 with bound substrate analog geranylgeranyl thiodiphosphate (GGSPP). In the GGSPP-bound form, GGSPP folds into a unique S-shaped conformation that probably reflects the substrate-bound state prior to ionization of the substrate GGPP. The folded framework of GGSPP is surrounded by hydrophobic residues and several aromatic and asparagine residues that are well-positioned to stabilize a series of reactive carbocation intermediates through a combination of cation-π and dipole charge interactions. The combined crystal structures and mutagenesis-based biochemical assays provide a structural basis for exquisite control of ring formation and stereochemistry during CotB2 catalysis.

PubMed: 28463490
DOI: 10.1021/acschembio.7b00154

Experimental method

X-RAY DIFFRACTION (1.8 Å)