IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
A unique cre site controls the catabolic response of two malate operons in Enterococcus feacalis
Autor/es:
ESPARIZ, M; MORTERA, P; BLANCATO, VS; SUÁREZ, CA; REPIZO, GD; ALARCÓN, S; MAGNI, C
Lugar:
Puerto Madryn
Reunión:
Congreso; XLVI Reunión Anual de SAIB; 2010
Institución organizadora:
Sociedad Argentina de Investigación en Bioquímica y Bilogía Molecular
Resumen:
Enterococcus faecalis is able to use malate in
aerobic and anaerobic conditions. The mae
locus of E. faecalis consist of two
putative divergent operons, maePE and
maeKR. The first operon codifies for
the malic enzyme (maeE) and for the
malate transporter (maeP). The second
operon encodes the two component system (TCS), composed by the membrane kinase sensor
(maeK) and the transcriptional
regulator (maeR). In a previous work we showed that inactivation of the maeR or maeE caused complete loss of malate
utilization in E. faecalis. In
this communication we demonstrated that both operons are specifically induced in
response to the presence of malate in the growth medium and are repressed by
the addition of PTS sugars. We performed transcriptional and mutagenesis
analysis and established that a unique cre site (catabolite-
responsive element) located between the -14 and -27 from maePE and -76 and -89 from maeKR transcriptional start sites
governed the glucose repression of both operons.