Symbiosis-specific expression of Rhizobium etli casA encoding a secreted calmodulin-related protein
AUTOR(ES)
Xi, Chuanwu
FONTE
The National Academy of Sciences
RESUMO
Symbiosis between Rhizobium and its leguminous host requires elaborate communication between the partners throughout the interaction process. A calmodulin-like protein, termed calsymin, was identified in Rhizobium etli; a calmodulin-related protein in a Gram-negative bacterium had not been described previously. Calsymin possesses three repeated homologous domains. Each domain contains two predicted EF-hand Ca2+-binding motifs. Ca2+-binding activity of calsymin was demonstrated on purified protein. R. etli efficiently secretes calsymin without N-terminal cleavage of the protein. The gene encoding calsymin, casA, is exclusively expressed during colonization and infection of R. etli with the host. Expression of casA is controlled by a repressor protein, termed CasR, belonging to the TetR family of regulatory proteins. Mutation of the casA gene affects the development of bacteroids during symbiosis and symbiotic nitrogen fixation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=27157Documentos Relacionados
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