IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
GOB: the only truly mononuclear broad spectrum zinc-â-
Autor/es:
LISA, M.; MORAN-BARRIO, J.; GONZALEZ, J.; COSTELLO, A.; TIERNEY, D.; ADRIANA SARA LIMANSKY; ALEJANDRO VIALE; VILA, A.
Lugar:
Rosario
Reunión:
Congreso; Sociedad Argentina de Biofisica; 2006
Resumen:
Metallo-â-lactamases (MâLs) are Zn(II) dependent enzymes with highly conserved metal
binding amino acid residues at the active site. We describe here the biochemical and
biophysical characterization of a recently discovered MâL: GOB from the opportunistic pathogen
binding amino acid residues at the active site. We describe here the biochemical and
biophysical characterization of a recently discovered MâL: GOB from the opportunistic pathogen
â-lactamases (MâLs) are Zn(II) dependent enzymes with highly conserved metal
binding amino acid residues at the active site. We describe here the biochemical and
biophysical characterization of a recently discovered MâL: GOB from the opportunistic pathogenâL: GOB from the opportunistic pathogen
Elizabethkingia meningoseptica [1]. MâLs related to GOB present two Zn(II) binding sites: Zn1
is coordinated by three His residues at the positions 116, 118 and 196, while Zn2 is ligated to
residues Asp120, His121 and His263. However, GOB presents a Gln residue at the position 116
instead of a His.
Spectroscopy data indicate that GOBs active site harbors only one Zn(II) ion. On the other
hand, kinetic studies indicate that GOB is a broad substrate-spectrum enzyme. This contrasts
with the behavior of all other known broad spectrum MâLs which are maximally active in their dinuclear
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.
is coordinated by three His residues at the positions 116, 118 and 196, while Zn2 is ligated to
residues Asp120, His121 and His263. However, GOB presents a Gln residue at the position 116
instead of a His.
Spectroscopy data indicate that GOBs active site harbors only one Zn(II) ion. On the other
hand, kinetic studies indicate that GOB is a broad substrate-spectrum enzyme. This contrasts
with the behavior of all other known broad spectrum MâLs which are maximally active in their dinuclear
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.
[1]. MâLs related to GOB present two Zn(II) binding sites: Zn1
is coordinated by three His residues at the positions 116, 118 and 196, while Zn2 is ligated to
residues Asp120, His121 and His263. However, GOB presents a Gln residue at the position 116
instead of a His.
Spectroscopy data indicate that GOBs active site harbors only one Zn(II) ion. On the other
hand, kinetic studies indicate that GOB is a broad substrate-spectrum enzyme. This contrasts
with the behavior of all other known broad spectrum MâLs which are maximally active in their dinuclear
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.
âLs which are maximally active in their dinuclear
forms.
In order to elucidate Zn(II) location in GOBs active site, two point mutants were generated.
Q116H-GOB presents spectral and kinetic characteristics that closely resemble those of the wt
enzyme. This indicates that residue Gln116 is neither a metal ligand nor essential for activity in
GOB. In contrast, D120S-GOB mutant shows a dramatic reduction in metal content and activity
comparing to those of the wild-type enzyme, demonstrating its essentiality for metal binding and
substrate hydrolysis.
The overall results indicate that GOB harbors one Zn(II) ion in the canonical site-2, coordinated
by residues D120, H121 and H263, therefore revealing a novel mononuclear Zn(II) site different
from all currently known MâLs.âLs.