title: Proteome analysis of the plant pathogen Xylella fastidiosa reveals major cellular and extracellular proteins and a peculiar codon bias distribution.
abstract: 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).
authors.affiliation: Departamento de Bioquimica, UNICAMP, Campinas, SP, Brazil.
authors.forename: Marcus Bustamante
authors.initials: MB
authors.lastname: Smolka
authors.forename: Daniel
authors.initials: D
authors.lastname: Martins-de-Souza
authors.forename: Daniel
authors.initials: D
authors.lastname: Martins
authors.forename: Flavia Vischi
authors.initials: FV
authors.lastname: Winck
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Santoro
authors.forename: Rafael Ramos
authors.initials: RR
authors.lastname: Castellari
authors.forename: Fernanda
authors.initials: F
authors.lastname: Ferrari
authors.forename: Itaraju Junior
authors.initials: IJ
authors.lastname: Brum
authors.forename: Eduardo
authors.initials: E
authors.lastname: Galembeck
authors.forename: Helvécio
authors.initials: H
authors.lastname: Della Coletta Filho
authors.forename: Marcos Antonio
authors.initials: MA
authors.lastname: Machado
authors.forename: Sergio
authors.initials: S
authors.lastname: Marangoni
authors.forename: Jose Camillo
authors.initials: JC
authors.lastname: Novello
mesh_terms: 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
chemical_list: D000975:Antioxidants; D001426:Bacterial Proteins; D003062:Codon; D010455:Peptides; D018272:Porins; D020543:Proteome; D007501:Iron