Isomerases;
Intramolecular oxidoreductases;
Transposing C=C bonds
BRITE hierarchy

S-methyl-5-thio-D-ribulose 1-phosphate 1,3-isomerase

(1) S-methyl-5-thio-D-ribulose 1-phosphate = S-methyl-1-thio-D-xylulose 5-phosphate [RN:R12718];
(2) S-methyl-5-thio-D-ribulose 1-phosphate = S-methyl-1-thio-D-ribulose 5-phosphate [RN:R12719]

R12718 R12719
Reaction

S-methyl-5-thio-D-ribulose 1-phosphate [CPD:C04582]

The enzyme, characterized from the bacterium Rhodospirillum rubrum, participates in methionine salvage from S-methyl-5'-thioadenosine. It is a RubisCO-like protein (RLP) that is not capable of carbon fixation, and catalyses an isomerization reaction that converts S-methyl-5-thio-D-ribulose 1-phosphate to a 3:1 mixture of S-methyl-1-thioxylulose 5-phosphate and S-methyl-1-thioribulose 5-phosphate. The reaction is an overall 1,3-proton transfer, which likely consists of two 1,2-proton transfer events.

EC 5.3.3.23 created 2021

1  [PMID:18826254]

Imker HJ, Singh J, Warlick BP, Tabita FR, Gerlt JA.

Mechanistic diversity in the RuBisCO superfamily: a novel isomerization reaction catalyzed by the RuBisCO-like protein from Rhodospirillum rubrum.

Biochemistry 47:11171-3 (2008)
DOI:10.1021/bi801685f

2  [PMID:23042035]

Erb TJ, Evans BS, Cho K, Warlick BP, Sriram J, Wood BM, Imker HJ, Sweedler JV, Tabita FR, Gerlt JA.

A RubisCO-like protein links SAM metabolism with isoprenoid biosynthesis.

Nat Chem Biol 8:926-32 (2012)
DOI:10.1038/nchembio.1087

[rru:Rru_A1998]