PDBsum entry 19hc

Electron transport

PDB id: 19hc

Contents

Protein chains

292 a.a. *

Ligands

ACT ×5

HEM ×18

Waters ×885

* Residue conservation analysis

PDB id:

19hc

Name:

Electron transport

Title:

Nine-haem cytochromE C from desulfovibrio desulfuricans atcc 27774

Structure:

Protein (nine-haem cytochromE C). Chain: a, b

Source:

Desulfovibrio desulfuricans. Organism_taxid: 876. Atcc: 27774. Cellular_location: periplasmic (presumed)

Biol. unit:

Dimer (from PQS)

Resolution:

1.80Å R-factor: 0.169

Authors:

P.M.Matias,R.Coelho,I.A.C.Pereira,A.V.Coelho,A.W.Thompson,L.Sieker, J.L.Gall,M.A.Carrondo

Key ref:

P.M.Matias et al. (1999). The primary and three-dimensional structures of a nine-haem cytochrome c from Desulfovibrio desulfuricans ATCC 27774 reveal a new member of the Hmc family. Structure, 7, 119-130. PubMed id: 10368280 DOI: 10.1016/S0969-2126(99)80019-7

Date:

27-Nov-98 Release date: 01-Dec-99

Protein chains

Q9RN68  (CYC9_DESDA) -  Nine-heme cytochrome c from Desulfovibrio desulfuricans (strain ATCC 27774 / DSM 6949 / MB)

Seq: 326 a.a.

Struc: 292 a.a.*

* PDB and UniProt seqs differ at 26 residue positions (black crosses)

DOI no: 10.1016/S0969-2126(99)80019-7

Structure 7:119-130 (1999)

PubMed id: 10368280

The primary and three-dimensional structures of a nine-haem cytochrome c from Desulfovibrio desulfuricans ATCC 27774 reveal a new member of the Hmc family.

P.M.Matias, R.Coelho, I.A.Pereira, A.V.Coelho, A.W.Thompson, L.C.Sieker, J.L.Gall, M.A.Carrondo.

ABSTRACT

BACKGROUND: Haem-containing proteins are directly involved in electron transfer as well as in enzymatic functions. The nine-haem cytochrome c (9Hcc), previously described as having 12 haem groups, was isolated from cells of Desulfovibrio desulfuricans ATCC 27774, grown under both nitrate- and sulphate-respiring conditions. RESULTS: Models for the primary and three-dimensional structures of this cytochrome, containing 292 amino acid residues and nine haem groups, were derived using the multiple wavelength anomalous dispersion phasing method and refined using 1.8 A diffraction data to an R value of 17.0%. The nine haem groups are arranged into two tetrahaem clusters, with Fe-Fe distances and local protein fold similar to tetrahaem cytochromes c3, while the extra haem is located asymmetrically between the two clusters. CONCLUSIONS: This is the first known three-dimensional structure in which multiple copies of a tetrahaem cytochrome c3-like fold are present in the same polypeptide chain. Sequence homology was found between this cytochrome and the C-terminal region (residues 229-514) of the high molecular weight cytochrome c from Desulfovibrio vulgaris Hildenborough (DvH Hmc). A new haem arrangement in domains III and IV of DvH Hmc hydrogenase from D. desulfuricans ATCC 27774, but that this reduction is faster in the presence of tetrahaem cytochrome c3. As Hmc has never been found in D. desulfuricans ATCC 27774, we propose that 9Hcc replaces it in this organism and is therefore probably involved in electron transfer across the membrane.

Selected figure(s)

Figure 4.
Figure 4. Domain structure of 9Hcc from D. desulfuricans ATCC 27774, established on the basis of comparison with the known structure of the tetrahaem cytochrome c[3] from the same organism. The different domains of the structure are colour-coded: the c[3]-like tetrahaem region of the N-terminal domain is represented in yellow (residues 1–107 and 125–132); the insertion containing the isolated haem-binding region is drawn in cyan (residues 108–124); the polypeptide segment connecting the two domains is represented in green (residues 133–176); the c[3]-like tetrahaem region of the C-terminal domain is in red (residues 177–205 and 224–292); and the insertion containing the second axial ligand of the isolated haem is shown in purple (residues 206–223).

The above figure is reprinted by permission from Cell Press: Structure (1999, 7, 119-130) copyright 1999.

Figure was selected by the author.