Proximity between nucleotide/dinucleotide and metal ion binding sites in DNA-dependent RNA polymerase from Escherichia coli. [Erratum to document cited in CA117:65481]

Biochemistry ◽  
1994 ◽  
Vol 33 (30) ◽  
pp. 9032-9032
Author(s):  
Suresh C. Tyagi ◽  
Felicia Y. H. Wu
Keyword(s):  
Escherichia Coli ◽  
Rna Polymerase ◽  
Binding Sites ◽  
Metal Ion ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Ion Binding Sites ◽  
Metal Ion Binding Sites

Terbium(III) luminescence study of the spatial relationship of tryptophan residues to the two metal ion binding sites of Escherichia coli glutamine synthetase

Biochemistry ◽  
1991 ◽  
Vol 30 (14) ◽  
pp. 3417-3421 ◽  
Author(s):  
Linda S. McNemar ◽  
Wann Yin Lin ◽  
Charles D. Eads ◽  
William M. Atkins ◽  
Patrice Dombrosky ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Binding Sites ◽  
Metal Ion ◽  
Spatial Relationship ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Tryptophan Residues ◽  
Ion Binding Sites ◽  
Relationship Of ◽  
Metal Ion Binding Sites

scholarly journals Cobalt activation of Escherichia coli 5'-nucleotidase is due to zinc ion displacement at only one of two metal-ion-binding sites

2003 ◽  
Vol 372 (2) ◽  
pp. 625-630 ◽  
Author(s):  
Lyle McMILLEN ◽  
Ifor R. BEACHAM ◽  
Dennis M. BURNS
Keyword(s):  
Escherichia Coli ◽  
Binding Site ◽  
Binding Sites ◽  
Metal Ion ◽  
Ion Binding ◽  
Nucleotidase Activity ◽  
Metal Ion Binding ◽  
E Coli ◽  
Ion Binding Sites ◽  
Metal Ion Binding Sites

Escherichia coli 5′-nucleotidase activity is stimulated 30- to 50-fold in vitro by the addition of Co2+. Seven residues from conserved sequence motifs implicated in the catalytic and metal-ion-binding sites of E. coli 5′-nucleotidase (Asp41, His43, Asp84, His117, Glu118, His217 and His252) were selected for modification using site-directed mutagenesis of the cloned ushA gene. On the basis of comparative studies between the resultant mutant proteins and the wild-type enzyme, a model is proposed for E. coli 5′-nucleotidase in which a Co2+ ion may displace the Zn2+ ion at only one of two metal-ion-binding sites; the other metal-ion-binding site retains the Zn2+ ion already present. The studies reported herein suggest that displacement occurs at the metal-ion-binding site consisting of residues Asp84, Asn116, His217 and His252, leading to the observed increase in 5′-nucleotidase activity.

Sign in / Sign up

Export Citation Format

Share Document