Absence of classical heat shock response in the citrus pathogen Xylella fastidiosa.
The fastidious bacterium Xylella fastidiosa is associated with important crop diseases worldwide. We have recently shown that X. fastidiosa is a peculiar organism having unusually low values of gene codon bias throughout its genome and, unexpectedly, in the group of the most abundant proteins. Here, we hypothesized that the lack of codon usage optimization in X. fastidiosa would incapacitate this organism to undergo quick and massive changes in protein expression as occurs in a classical stress response. Proteomic analysis of the response to heat stress in X. fastidiosa revealed that no changes in protein expression can be detected. Moreover, stress-inducible proteins identified in the closely related citrus pathogen Xanthomonas axonopodis pv citri were found to be constitutively expressed in X. fastidiosa. These proteins have extremely high codon bias values in the X. citri and other well-studied organisms, but low values in X. fastidiosa. Because biased codon usage is well known to correlate to the rate of protein synthesis, we speculate that the peculiar codon bias distribution in X. fastidiosa is related to the absence of a classical stress response, and, probably, alternative strategies for survival of X. fastidiosa under stressfull conditions.
Martins-de-Souza
Daniel
D
Departamento de Bioquímica, Inst. de Biologia, UNICAMP, Campinas, SP, Brazil.
Martins
Daniel
D
Astua-Monge
Gustavo
G
Coletta-Filho
Helvécio Della
HD
Winck
Flavia Vischi
FV
Baldasso
Paulo Aparecido
PA
de Oliveira
Bruno Menezes
BM
Marangoni
Sérgio
S
Machado
Marcos Antônio
MA
Novello
José Camillo
JC
Smolka
Marcus Bustamante
MB
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018835:Chaperonin 10 / Q000235:genetics / Q000378:metabolism; D002957:Citrus / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D018869:Heat-Shock Response; D010935:Plant Diseases / Q000382:microbiology; D014974:Xanthomonas / Q000472:pathogenicity / Q000502:physiology; D044167:Xylella / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*
D001426:Bacterial Proteins; D018835:Chaperonin 10; D006360:Heat-Shock Proteins; C113725:HspA protein, bacteria