Proteome analysis of the plant pathogen Xylella fastidiosa reveals major cellular and extracellular proteins and a peculiar codon bias distribution.
The bacteria Xylella fastidiosa is the causative agent of a number of economically important crop diseases, including citrus variegated chlorosis. Although its complete genome is already sequenced, X. fastidiosa is very poorly characterized by biochemical approaches at the protein level. In an initial effort to characterize protein expression in X. fastidiosa we used one- and two-dimensional gel electrophoresis and mass spectrometry to identify the products of 142 genes present in a whole cell extract and in an extracellular fraction of the citrus isolated strain 9a5c. Of particular interest for the study of pathogenesis are adhesion and secreted proteins. Homologs to proteins from three different adhesion systems (type IV fimbriae, mrk pili and hsf surface fibrils) were found to be coexpressed, the last two being detected only as multimeric complexes in the high molecular weight region of one-dimensional electrophoresis gels. Using a procedure to extract secreted proteins as well as proteins weakly attached to the cell surface we identified 30 different proteins including toxins, adhesion related proteins, antioxidant enzymes, different types of proteases and 16 hypothetical proteins. These data suggest that the intercellular space of X. fastidiosa colonies is a multifunctional microenvironment containing proteins related to in vivo bacterial survival and pathogenesis. A codon usage analysis of the most expressed proteins from the whole cell extract revealed a low biased distribution, which we propose is related to the slow growing nature of X. fastidiosa. A database of the X. fastidiosa proteome was developed and can be accessed via the internet (URL: www.proteome.ibi.unicamp.br).
Smolka
Marcus Bustamante
MB
Departamento de Bioquimica, UNICAMP, Campinas, SP, Brazil.
Martins-de-Souza
Daniel
D
Martins
Daniel
D
Winck
Flavia Vischi
FV
Santoro
Carlos Eduardo
CE
Castellari
Rafael Ramos
RR
Ferrari
Fernanda
F
Brum
Itaraju Junior
IJ
Galembeck
Eduardo
E
Della Coletta Filho
Helvécio
H
Machado
Marcos Antonio
MA
Marangoni
Sergio
S
Novello
Jose Camillo
JC
D000975:Antioxidants / Q000737:chemistry; D001422:Bacterial Adhesion; D001426:Bacterial Proteins / Q000737:chemistry*; D003062:Codon; D019992:Databases as Topic; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D020563:Gammaproteobacteria / Q000737:chemistry / Q000378:metabolism*; D016680:Genome, Bacterial; D007091:Image Processing, Computer-Assisted; D007501:Iron / Q000378:metabolism; D013058:Mass Spectrometry; D016366:Open Reading Frames; D010455:Peptides / Q000737:chemistry; D010935:Plant Diseases / Q000382:microbiology; D018272:Porins / Q000502:physiology; D020543:Proteome
D000975:Antioxidants; D001426:Bacterial Proteins; D003062:Codon; D010455:Peptides; D018272:Porins; D020543:Proteome; D007501:Iron