Sequence analysis reveals new membrane anchor of reaction centre‐bound cytochromes possibly related to PufX

FEBS Letters

Hucke, Oliver¹  Drews, Gerhart³  Schiltz, Emile²  Labahn, Andreas¹ 

[1] Institut für Physikalische Chemie, Albertstr. 23a, Universität Freiburg, D-79104 Freiburg, Germany;Institut für Organische Chemie und Biochemie, Albertstr. 21, Universität Freiburg, D-79104 Freiburg, Germany;Institut für Biologie II, Mikrobiologie, Schänzlestr. 1, Universität Freiburg, D-79104 Freiburg, Germany

关键词: Bacterial photosynthesis;    Photosynthetic reaction center;    Tetrahaem subunit;    Cytochrome;    PufX;    Roseobacter denitrificans;    A.;    Acidophilum;    Achr.;    Allochromatium;    B.;    Blastochloris;    Chl.;    Chloroflexus;    E.;    Ectothiorhodospira;    R.;    Roseobacter;    Rh.;    Rhodobacter;    Rsp.;    Rhodospirillum;    Rv.;    Rubrivivax;    Rvu.;    Rhodovolum;    T.;    Thermochromatium;    RC;    reaction centre;    LHI;    light-harvesting complex I;   

DOI  :  10.1016/S0014-5793(02)03899-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Most of the bacterial photosynthetic reaction centres known to date contain a cytochrome subunit with four covalently bound haem groups. In the case of Blastochloris viridis, this reaction centre subunit is anchored in the membrane by a lipid molecule covalently attached to the cysteine which forms the N-terminus of the mature protein after processing by a signal peptidase. We show that posttranslational N-terminal cleavage of the cytochrome subunit does not occur in the aerobic photosynthetic bacterium Roseobacter denitrificans. From sequence analysis of the resulting elongated N-terminus it follows that a transmembrane helix is anchoring the reaction centre-bound cytochrome in the membrane. Comparative sequence analysis strongly suggests that all cytochrome subunits lacking the lipid coupling cysteine share this structural feature. Comparison of the N-terminal segment of the cytochrome subunit of Roseobacter denitrificans with the sequences of the PufX proteins from Rhodobacter sphaeroides and Rhodobacter capsulatus suggests a phylogenetic relation.

【 授权许可】

Unknown