PDBsum entry: 1m41

Oxidoreductase

PDB id: 1m41

Contents

Protein chains

328 a.a. *

Waters ×310

* Residue conservation analysis

PDB id:

1m41

Name:

Oxidoreductase

Title:

Crystal structure of escherichia coli alkanesulfonate monooxygenase ssud at 2.3 a resolution

Structure:

Fmnh2-dependent alkanesulfonate monooxygenase. Chain: a, b. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Gene: ssud. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Tetramer (from PDB file)

Resolution:

2.30Å R-factor: 0.235 R-free: 0.275

Authors:

E.Eichhorn,C.A.Davey,D.F.Sargent,T.Leisinger,T.J.Richmond

Key ref:

E.Eichhorn et al. (2002). Crystal structure of Escherichia coli alkanesulfonate monooxygenase SsuD. J Mol Biol, 324, 457-468. PubMed id: 12445781 DOI: 10.1016/S0022-2836(02)01069-0

Date:

02-Jul-02 Release date: 11-Dec-02

Protein chains

P80645  (SSUD_ECOLI) -  Alkanesulfonate monooxygenase

Seq: 381 a.a.

Struc: 328 a.a.

Enzyme reactions

• Enzyme class: E.C.1.14.14.5 - Alkanesulfonate monooxygenase.
• Reaction: An alkanesufonate (R-CH₂-SO(3)H) + FMNH₂ + O₂ = an aldehyde (R-CHO) + FMN + sulfite + H(2)O

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

 Gene Ontology (GO) functional annotation 

• Biological process: oxidation-reduction process (2 terms)
• Biochemical function: oxidoreductase activity (4 terms)

reference

DOI no: 10.1016/S0022-2836(02)01069-0

J Mol Biol 324:457-468 (2002)

PubMed id: 12445781

Crystal structure of Escherichia coli alkanesulfonate monooxygenase SsuD.

E.Eichhorn, C.A.Davey, D.F.Sargent, T.Leisinger, T.J.Richmond.

ABSTRACT

The FMNH(2)-dependent alkanesulfonate monooxygenase SsuD catalyzes the conversion of alkanesulfonates to the corresponding aldehyde and sulfite. The enzyme allows Escherichia coli to use a wide range of alkanesulfonates as sulfur sources for growth when sulfate or cysteine are not available. The structure of SsuD was solved using the multiwavelength anomalous dispersion method from only four ordered selenium sites per asymmetric unit (one site per 20,800 Da). The final model includes 328 of 380 amino acid residues and was refined to an R-factor of 23.5% (R(free)=27.5%) at 2.3A resolution. The X-ray crystal structure of SsuD shows a homotetrameric state for the enzyme, each subunit being composed of a TIM-barrel fold enlarged by four insertion regions that contribute to intersubunit interactions. SsuD is structurally related to a bacterial luciferase and an archaeal coenzyme F(420)-dependent reductase in spite of a low level of sequence identity with these enzymes. The structural relationship is not limited to the beta-barrel region; it includes most but not all extension regions and shows distinct properties for the SsuD TIM-barrel. A likely substrate-binding site is postulated on the basis of the SsuD structure presented here, results from earlier biochemical studies, and structure relatedness to bacterial luciferase. SsuD is related to other FMNH(2)-dependent monooxygenases that show distant sequence relationship to luciferase. Thus, the structure reported here provides a model for enzymes belonging to this family and suggests that they might all fold as TIM-barrel proteins.

Selected figure(s)

Figure 2.
Figure 2. Examples of (a) the experimental electron density map used to build the initial model and (b) the final 2|F[obs]| -|F[calc]| electron density map. Both maps are contoured at 1.0 s. The view shows the N terminus of SsuD. The polypeptide chain is shown in yellow. The green color indicates the sulfur atom of residue Met4.

Figure 3.
Figure 3. Structure of E. coli alkanesulfonate monooxygenase SsuD. (a) A stereo view perpendicular to the b-barrel axis. (b) A stereo view along the axis of the b-barrel looking towards the C-terminal ends of the b-strands. (c) Topology diagram showing the secondary structural elements of SsuD (chain A), represented as arrows for b-strands and cylinders for helices. The core of the (b/a)[8]-barrel is drawn along the middle, insertion regions are drawn above or below the core of the b-barrel. The b-barrel is closed by hydrogen-bonding of strand b8 to b1. The numbers indicate the beginning and end of each secondary structural element. Helices a4a, a7b and a8a are 3[10]-helices. Chains A and B have identical topologies.

The above figures are reprinted by permission from Elsevier: J Mol Biol (2002, 324, 457-468) copyright 2002.

Figures were selected by the author.