PDBsum entry 4m2k

Transferase

PDB id: 4m2k

Contents

Protein chain

382 a.a.

Ligands

PLP

Waters ×210

PDB id:

4m2k

Name:

Transferase

Title:

Crystal structure of plp-dependent cyclase orfr in complex with plp

Structure:

Aminotransferase. Chain: a. Synonym: orfp. Engineered: yes

Source:

Streptomyces lavendulae. Organism_taxid: 58340. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.00Å R-factor: 0.172 R-free: 0.196

Authors:

C.Y.Chang,Y.C.Liu,S.Y.Lyu,C.C.Wu,T.L.Li

Key ref:

C.Y.Chang et al. (2014). Biosynthesis of streptolidine involved two unexpected intermediates produced by a dihydroxylase and a cyclase through unusual mechanisms. Angew Chem Int Ed Engl, 53, 1943-1948. PubMed id: 24505011 DOI: 10.1002/anie.201307989

Date:

05-Aug-13 Release date: 18-Jun-14

Protein chain

G9MBV4  (G9MBV4_STRLA) -  Aminotransferase from Streptomyces lavendulae subsp. lavendulae

Seq: 386 a.a.

Struc: 382 a.a.

Enzyme reactions

• Enzyme class: E.C.4.3.2.- - ?????

DOI no: 10.1002/anie.201307989

Angew Chem Int Ed Engl 53:1943-1948 (2014)

PubMed id: 24505011

Biosynthesis of streptolidine involved two unexpected intermediates produced by a dihydroxylase and a cyclase through unusual mechanisms.

C.Y.Chang, S.Y.Lyu, Y.C.Liu, N.S.Hsu, C.C.Wu, C.F.Tang, K.H.Lin, J.Y.Ho, C.J.Wu, M.D.Tsai, T.L.Li.

ABSTRACT

Streptothricin-F (STT-F), one of the early-discovered antibiotics, consists of three components, a β-lysine homopolymer, an aminosugar D-gulosamine, and an unusual bicyclic streptolidine. The biosynthesis of streptolidine is a long-lasting but unresolved puzzle. Herein, a combination of genetic/biochemical/structural approaches was used to unravel this problem. The STT gene cluster was first sequenced from a Streptomyces variant BCRC 12163, wherein two gene products OrfP and OrfR were characterized in vitro to be a dihydroxylase and a cyclase, respectively. Thirteen high-resolution crystal structures for both enzymes in different reaction intermediate states were snapshotted to help elucidate their catalytic mechanisms. OrfP catalyzes an Fe(II) -dependent double hydroxylation reaction converting L-Arg into (3R,4R)-(OH)2 -L-Arg via (3S)-OH-L-Arg, while OrfR catalyzes an unusual PLP-dependent elimination/addition reaction cyclizing (3R,4R)-(OH)2 -L-Arg to the six-membered (4R)-OH-capreomycidine. The biosynthetic mystery finally comes to light as the latter product was incorporation into STT-F by a feeding experiment.