Nucleophile in the active site of Escherichia coli galactose-1-phosphate uridylyltransferase: degradation of the uridylyl-enzyme intermediate to N3-phosphohistidine

Biochemistry ◽  
1979 ◽  
Vol 18 (14) ◽  
pp. 2980-2984 ◽  
Author(s):  
Sue-Lein Lee Yang ◽  
Perry A. Frey
Keyword(s):  
Escherichia Coli ◽  
Active Site ◽  
Enzyme Intermediate

scholarly journals Interplay of nucleophilic catalysis with proton transfer in the nitrile reductase QueF from Escherichia coli

2019 ◽  
Vol 9 (3) ◽  
pp. 842-853 ◽  
Author(s):  
Jihye Jung ◽  
Jan Braun ◽  
Tibor Czabany ◽  
Bernd Nidetzky
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Active Site ◽  
Nucleophilic Catalysis ◽  
Proton Relay ◽  
Network Of Hydrogen Bonds ◽  
Site Network ◽  
Nitrile Reduction ◽  
Enzyme Intermediate

Proton relay through an active-site network of hydrogen bonds promotes enzymatic nitrile reduction to amine via a covalent thioimidate enzyme intermediate.

scholarly journals Derived amino acid sequence and identification of active site residues of Escherichia coli beta-hydroxydecanoyl thioester dehydrase.

1988 ◽  
Vol 263 (10) ◽  
pp. 4641-4646 ◽  
Author(s):  
J E Cronan ◽  
W B Li ◽  
R Coleman ◽  
M Narasimhan ◽  
D de Mendoza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Active Site ◽  
Active Site Residues

scholarly journals Crystal Structure of Escherichia coli Agmatinase: Catalytic Mechanism and Residues Relevant for Substrate Specificity

2021 ◽  
Vol 22 (9) ◽  
pp. 4769
Author(s):  
Pablo Maturana ◽  
María S. Orellana ◽  
Sixto M. Herrera ◽  
Ignacio Martínez ◽  
Maximiliano Figueroa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Active Site ◽  
Catalytic Mechanism ◽  
Conformational Dynamics ◽  
High Specificity ◽  
Arginine Decarboxylase ◽  
Space Groups ◽  
X Ray Crystallography ◽  
High Dynamics ◽  
Dynamics Simulations

Agmatine is the product of the decarboxylation of L-arginine by the enzyme arginine decarboxylase. This amine has been attributed to neurotransmitter functions, anticonvulsant, anti-neurotoxic, and antidepressant in mammals and is a potential therapeutic agent for diseases such as Alzheimer’s, Parkinson’s, and cancer. Agmatinase enzyme hydrolyze agmatine into urea and putrescine, which belong to one of the pathways producing polyamines, essential for cell proliferation. Agmatinase from Escherichia coli (EcAGM) has been widely studied and kinetically characterized, described as highly specific for agmatine. In this study, we analyze the amino acids involved in the high specificity of EcAGM, performing a series of mutations in two loops critical to the active-site entrance. Two structures in different space groups were solved by X-ray crystallography, one at low resolution (3.2 Å), including a guanidine group; and other at high resolution (1.8 Å) which presents urea and agmatine in the active site. These structures made it possible to understand the interface interactions between subunits that allow the hexameric state and postulate a catalytic mechanism according to the Mn2+ and urea/guanidine binding site. Molecular dynamics simulations evaluated the conformational dynamics of EcAGM and residues participating in non-binding interactions. Simulations showed the high dynamics of loops of the active site entrance and evidenced the relevance of Trp68, located in the adjacent subunit, to stabilize the amino group of agmatine by cation-pi interaction. These results allow to have a structural view of the best-kinetic characterized agmatinase in literature up to now.

scholarly journals Active site stoichiometry of L-phenylalanine: tRNA ligase from Escherichia coli K(-10).

1975 ◽  
Vol 250 (19) ◽  
pp. 7668-7674
Author(s):  
P Bartmann ◽  
T Hanke ◽  
E Holler
Keyword(s):  
Escherichia Coli ◽  
Active Site
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