PDBsum entry 2a89

Oxidoreductase

PDB id: 2a89

Contents

Protein chains

385 a.a. *

Ligands

FCG ×2

PO4

Metals

_CL ×3

Waters ×980

* Residue conservation analysis

PDB id:

2a89

Name:

Oxidoreductase

Title:

Monomeric sarcosine oxidase: structure of a covalently flavinylated amine oxidizing enzyme

Structure:

Monomeric sarcosine oxidase. Chain: a, b. Synonym: msox. Engineered: yes

Source:

Bacillus sp.. Organism_taxid: 69000. Strain: b-0618. Gene: soxa, sox. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Monomer (from PQS)

Resolution:

1.85Å R-factor: 0.178 R-free: 0.221

Authors:

Z.-W.Chen,G.Zhao,S.Martinovic,M.S.Jorns,F.S.Mathews

Key ref:

Z.W.Chen et al. (2005). Structure of the sodium borohydride-reduced N-(cyclopropyl)glycine adduct of the flavoenzyme monomeric sarcosine oxidase. Biochemistry, 44, 15444-15450. PubMed id: 16300392 DOI: 10.1021/bi0515422

Date:

07-Jul-05 Release date: 17-Jan-06

Protein chains

P40859  (MSOX_BACB0) -  Monomeric sarcosine oxidase from Bacillus sp. (strain B-0618)

Seq: 390 a.a.

Struc: 385 a.a.

Enzyme reactions

• Enzyme class: E.C.1.5.3.1 - sarcosine oxidasee (formaldehyde-forming).
• Reaction: sarcosine + O2 + H2O = formaldehyde + glycine + H2O2
• Cofactor: FAD

FAD (Bound ligand (Het Group name = FCG) matches with 92.98% similarity)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1021/bi0515422

Biochemistry 44:15444-15450 (2005)

PubMed id: 16300392

Structure of the sodium borohydride-reduced N-(cyclopropyl)glycine adduct of the flavoenzyme monomeric sarcosine oxidase.

Z.W.Chen, G.Zhao, S.Martinovic, M.S.Jorns, F.S.Mathews.

ABSTRACT

Monomeric sarcosine oxidase (MSOX) is a flavoprotein that contains covalently bound FAD [8a-(S-cysteinyl)FAD] and catalyzes the oxidation of sarcosine (N-methylglycine) and other secondary amino acids, such as l-proline. Our previous studies showed that N-(cyclopropyl)glycine (CPG) acts as a mechanism-based inactivator of MSOX [Zhao, G., et al. (2000) Biochemistry 39, 14341-14347]. The reaction results in the formation of a modified reduced flavin that can be further reduced and stabilized by treatment with sodium borohydride. The borohydride-reduced CPG-modified enzyme exhibits a mass increase of 63 +/- 2 Da as compared with native MSOX. The crystal structure of the modified enzyme, solved at 1.85 A resolution, shows that FAD is the only site of modification. The modified FAD contains a fused five-membered ring, linking the C(4a) and N(5) atoms of the flavin ring, with an additional oxygen atom bound to the carbon atom attached to N(5) and a tetrahedral carbon atom at flavin C(4) with a hydroxyl group attached to C(4). On the basis of the crystal structure of the borohydride-stabilized adduct, we conclude that the labile CPG-modified flavin is a 4a,5-dihydroflavin derivative with a substituent derived from the cleavage of the cyclopropyl ring in CPG. The results are consistent with CPG-mediated inactivation in a reaction initiated by single electron transfer from the amine function in CPG to FAD in MSOX, followed by collapse of the radical pair to yield a covalently modified 4a,5-dihydroflavin.