Protein coding palindromes are a unique but recurrent feature in Rickettsia.
Rickettsia are unique in inserting in-frame a number of palindromic sequences within protein coding regions. In this study, we extensively analyzed repeated sequences in the genome of Rickettsia conorii and examined their locations in regard to coding versus noncoding regions. We identified 656 interspersed repeated sequences classified into 10 distinct families. Of the 10 families, three palindromic sequence families showed clear cases of insertions into open reading frames (ORFs). The location of those in-frame insertions appears to be always compatible with the encoded protein three-dimensional (3-D) fold and function. We provide evidence for a progressive loss of the palindromic property over time after the insertions. This comprehensive study of Rickettsia repeats confirms and extends our previous observations and further indicates a significant role of selfish DNAs in the creation and modification of proteins.
Ogata
Hiroyuki
H
Information Génétique & Structurale, CNRS-AVENTIS UMR 1889, 13402 Marseille Cedex 20, France. Hiroyuki.Ogata@igs.cnrs-mrs.fr
Audic
Stéphane
S
Abergel
Chantal
C
Fournier
Pierre-Edouard
PE
Claverie
Jean-Michel
JM
D000595:Amino Acid Sequence / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D001482:Base Composition / Q000235:genetics; D001483:Base Sequence; D019295:Computational Biology / Q000379:methods; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary / Q000235:genetics; D020114:Rickettsia conorii / Q000737:chemistry / Q000235:genetics*
D001426:Bacterial Proteins