PDBsum entry 1jgx

Photosynthesis

PDB id: 1jgx

Contents

Protein chains

281 a.a. *

302 a.a. *

240 a.a. *

Ligands

BCL ×4

BPH ×2

U10

SPO

Metals

_FE

Waters ×112

* Residue conservation analysis

PDB id:

1jgx

Name:

Photosynthesis

Title:

Photosynthetic reaction center mutant with thr m 21 replaced with asp

Structure:

Photosynthetic reaction center l subunit. Chain: l. Synonym: reaction center protein l chain. Engineered: yes. Photosynthetic reaction center m subunit. Chain: m. Synonym: reaction center protein m chain. Engineered: yes. Mutation: yes.

Source:

Rhodobacter sphaeroides. Organism_taxid: 1063. Expressed in: rhodobacter sphaeroides 2.4.1. Expression_system_taxid: 272943.

Biol. unit:

Trimer (from PQS)

Resolution:

3.01Å R-factor: 0.211 R-free: 0.249

Authors:

A.Camara-Artigas,C.L.Magee,J.C.Williams,J.P.Allen

Key ref:

A.Camara-Artigas et al. (2001). Individual interactions influence the crystalline order for membrane proteins. Acta Crystallogr D Biol Crystallogr, 57, 1281-1286. PubMed id: 11526320 DOI: 10.1107/S090744490101109X

Date:

27-Jun-01 Release date: 05-Sep-01

Protein chain

P0C0Y8  (RCEL_CERSP) -  Reaction center protein L chain from Cereibacter sphaeroides

Seq: 282 a.a.

Struc: 281 a.a.

Protein chain

P0C0Y9  (RCEM_CERSP) -  Reaction center protein M chain from Cereibacter sphaeroides

Seq: 308 a.a.

Struc: 302 a.a.*

Protein chain

P0C0Y7  (RCEH_CERSP) -  Reaction center protein H chain from Cereibacter sphaeroides

Seq: 260 a.a.

Struc: 240 a.a.

* PDB and UniProt seqs differ at 1 residue position (black cross)

DOI no: 10.1107/S090744490101109X

Acta Crystallogr D Biol Crystallogr 57:1281-1286 (2001)

PubMed id: 11526320

Individual interactions influence the crystalline order for membrane proteins.

A.Camara-Artigas, C.L.Magee, J.C.Williams, J.P.Allen.

ABSTRACT

The role of contact interactions in the crystallization of membrane proteins was assessed by mutation of amino-acid residues on the surface of the reaction center from Rhodobacter sphaeroides. Five single-site mutants were constructed, with changes in contact regions found in the trigonal and tetragonal forms but not the orthorhombic form. Crystallization trials for the tetragonal form yielded either no crystals or crystals with an altered morphology, whereas crystals grew in the other two forms, indicating that these interactions are essential for the stability of the tetragonal crystals. Changes in the structures determined by X-ray diffraction of trigonal crystals for each mutant were related to the quality of the diffraction. Significant differences in the resolution limit of the crystals were associated with the loss of specific interactions between neighboring proteins. The results suggest that the contact regions are crucial for obtaining highly ordered crystals of membrane proteins.

Selected figure(s)

Figure 1.
Figure 1 Structure of the wild-type reaction center from R. sphaeroides. (a) Backbone with the residues that have been found in a contact site in any one of the three crystal forms. All of the residues are located in the hydrophilic regions away from the central membrane-spanning region. The three residues at which mutations were made are labeled. (b) One of the contact interactions that is found only in the tetragonal form. Shown are residues GluL205 of one protein (shaded with atom types colored) and TyrM76 and LysM110 of a neighboring protein (shaded light tan). The residues form a bridge and hydrogen bonds that probably contribute to the high degree of crystalline order of this form.

Figure 4.
Figure 4 Stereo diagram of a contact region for the trigonal form in the wild type (blue) and the EL(L205) mutant (red). In the wild type, GluL205 interacts with HisH68, which is part of a loop formed by residues H68-H74 that is close to the same loop of a symmetry-related protein. This contact interaction is mediated by water molecules (blue) associated with ThrH72 and ThrH74. The substitution of Leu for Glu at L205 results in the association of a molecule, probably an ion (red), near L205 and H68 and loss of the bridging water molecules.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2001, 57, 1281-1286) copyright 2001.

Figures were selected by an automated process.