INVESTIGADORES
ESPARIZ Martin
congresos y reuniones científicas
Título:
A novel bacterial metal-ion sensing and detoxification system
Autor/es:
FERNANDO C. SONCINI; SUSANA K. CHECA; MARTÍN ESPARIZ; MARÍA E. PÉREZ AUDERO
Lugar:
Pinamar, Buenos Aires, Argentina.
Reunión:
Congreso; 10th congress of Panamerican Association for Biochemistry and Molecular Biology (PABMB), 41th Annual Meeting of Argentine Society for Biochemistry and Molecular Biology (SAIB), 20th Annual Meeting of Argentine Society for Neurochemistry (SAN).; 2005
Institución organizadora:
Sociedad Argentina de Bioquímica y Biología Molecular.
Resumen:
The MerR
family is a group of transcriptional regulators with similar N-terminal DNA
binding regions and C-terminal effector binding domains that respond
specifically to certain environmental stimuli, such as heavy metals, oxidative
stress or antibiotics. Among the heavy metal responsive regulators, different
subfamilies can be distinguished based on key residues in their sequences,
including a group that recognizes Cu(I); a separate group that specifically
senses divalent metals such as Zn(II), Co(II), Cd(II), and Pb(II); and the
group of Hg(II) responsive regulators. My group has characterized a three-gene Salmonella-specific locus coding for a
protein with high homology to the MerR-like copper-responsive regulators, a
metal-transporting P-type ATPase, and a polypeptide with homology to copper
chaperones. Activation of this locus depends on both the intactness of the
regulator and micromolar concentration of Au(III) salts in the culture medium,
and it is not affected by addition of other mono or divalent heavy metal
cations. In addition, a strain deleted in the locus was highly susceptible to
gold salts, highlighting its role in gold detoxification. This is the first
gold sensing and detoxification system identified in bacteria. This
horizontally acquired system allows Salmonella
to monitor and to withstand environments with high concentration of gold salts.