Structure prediction for the di-heme cytochrome b561 protein family |
| |
Authors: | Bashtovyy Denys Bérczi Alajos Asard Han Páli Tibor |
| |
Institution: | (1) Institute of Biophysics, Biological Research Centre, Szeged, HU;(2) Beadle Center for Genetic Research, University of Nebraska-Lincoln, Lincoln, Nebraska, US |
| |
Abstract: | Summary. Atomic models possessing the common structural features identified for the cytochrome b
561 (cyt b
561) protein family are presented. A detailed and extensive sequence analysis was performed in order to identify and characterize
protein sequences in this family of transmembrane electron transport proteins. According to transmembrane helix predictions,
all sequences contain 6 transmembrane helices of which 2–6 are located closely in the same regions of the 26 sequences in
the alignment. A mammalian (Homo sapiens) and a plant (Arabidopsis thaliana) sequence were selected to build 3-dimensional structures at atomic detail using molecular modeling tools. The main structural
constraints included the 2 pairs of heme-ligating His residues that are fully conserved in the family and the lipid-facing
sides of the helices, which were also very well conserved. The current paper proposes 3-dimensional structures which to our
knowledge are the first ones for any protein in the cyt b
561 family. The highly conserved His residues anchoring the two hemes on the cytoplasmic side and noncytoplasmic side of the
membrane are in all proteins located in the transmembrane helices 2, 4 and 3, 5, respectively. Several highly conserved amino
acids with aromatic side chain are identified between the two heme ligation sites. These residues may constitute a putative
transmembrane electron transport pathway. The present study demonstrates that the structural features in the cyt b
561 family are well conserved at both the sequence and the protein level. The central 4-helix core represents a transmembrane
electron transfer architecture that is highly conserved in eukaryotic species.
Received May 12, 2002; accepted September 20, 2002; published online May 21, 2003
RID="*"
ID="*" Correspondence and reprints: Institute of Biophysics, Biological Research Centre, P.O. Box 521, 6701 Szeged, Hungary.
E-mail: tpali@nucleus.szbk.u-szeged.hu |
| |
Keywords: | : Cytochrome b561 Structure prediction Heme protein Protein family Ascorbic acid Electron transport |
本文献已被 PubMed SpringerLink 等数据库收录! |
|