scholarly journals pH Dependence of a Mammalian Polyamine Oxidase: Insights into Substrate Specificity and the Role of Lysine 315†

Biochemistry ◽  
2009 ◽  
Vol 48 (7) ◽  
pp. 1508-1516 ◽  
Author(s):  
Michelle Henderson Pozzi ◽  
Vijay Gawandi ◽  
Paul F. Fitzpatrick
Keyword(s):  
Substrate Specificity ◽  
Ph Dependence ◽  
Polyamine Oxidase

scholarly journals Mechanistic Studies of the Yeast Polyamine Oxidase Fms1: Kinetic Mechanism, Substrate Specificity, and pH Dependence

Biochemistry ◽  
2010 ◽  
Vol 49 (49) ◽  
pp. 10440-10448 ◽  
Author(s):  
Mariya S. Adachi ◽  
Jason M. Torres ◽  
Paul F. Fitzpatrick
Keyword(s):  
Substrate Specificity ◽  
Ph Dependence ◽  
Kinetic Mechanism ◽  
Polyamine Oxidase ◽  
Mechanistic Studies

Possible role of a histidine residue in the substrate specificity of yeast d-aspartate oxidase

2015 ◽  
pp. mvv108 ◽  
Author(s):  
Shouji Takahashi ◽  
Kozue Shimada ◽  
Shunsuke Nozawa ◽  
Masaru Goto ◽  
Katsumasa Abe ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Histidine Residue

Role of the FAD-dependent polyamine oxidase in the selective formation of N1,N8-bis(γ- glutamyl)spermidine protein cross-links1

2007 ◽  
Vol 35 (2) ◽  
pp. 396-400 ◽  
Author(s):  
A. Lentini ◽  
P. Mattioli ◽  
B. Provenzano ◽  
A. Abbruzzese ◽  
M. Caraglia ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Polyamine Oxidase ◽  
Polyamine Metabolism ◽  
Suitable Model ◽  
Cross Link ◽  
Cellular Mechanisms ◽  
Preferential Formation ◽  
Cross Links ◽  
Selective Formation

Protein-bound γ-glutamylpolyamines have highlighted a new pathway in polyamine metabolism. Human foreskin keratinocytes offer a suitable model for this study. Indeed, they develop polymerized envelopes, as they differentiate, rich in ϵ-(γ-glutamyl)lysine and N1,N8-bis(γ-glutamyl)spermidine cross-links. We have found that the selective oxidation of N1-(γ-glutamyl)spermidine and N-(γ-glutamyl)spermine by FAD-dependent polyamine oxidase (PAO) may be one of the cellular mechanisms regulating the preferential formation of a sterically defined bis(γ-glutamyl)spermidine cross-link. The significance of this finding is unknown, but it suggests that the target of this PAO-modulation is to achieve the biochemical prerequisite for production of a normal epidermal stratum corneum.

scholarly journals Molecular Basis of Substrate Recognition of Endonuclease Q from the Euryarchaeon Pyrococcus furiosus

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Miyako Shiraishi ◽  
Shigenori Iwai
Keyword(s):  
Dna Repair ◽  
Bacillus Subtilis ◽  
Substrate Specificity ◽  
Molecular Basis ◽  
Pyrococcus Furiosus ◽  
Substrate Recognition ◽  
Base Flipping ◽  
Content Type ◽  
Cleavage Activity

ABSTRACT Endonuclease Q (EndoQ), a DNA repair endonuclease, was originally identified in the hyperthermophilic euryarchaeon Pyrococcus furiosus in 2015. EndoQ initiates DNA repair by generating a nick on DNA strands containing deaminated bases and an abasic site. Although EndoQ is thought to be important for maintaining genome integrity in certain bacteria and archaea, the underlying mechanism catalyzed by EndoQ remains unclear. Here, we provide insights into the molecular basis of substrate recognition by EndoQ from P. furiosus (PfuEndoQ) using biochemical approaches. Our results of the substrate specificity range and the kinetic properties of PfuEndoQ demonstrate that PfuEndoQ prefers the imide structure in nucleobases along with the discovery of its cleavage activity toward 5,6-dihydrouracil, 5-hydroxyuracil, 5-hydroxycytosine, and uridine in DNA. The combined results for EndoQ substrate binding and cleavage activity analyses indicated that PfuEndoQ flips the target base from the DNA duplex, and the cleavage activity is highly dependent on spontaneous base flipping of the target base. Furthermore, we find that PfuEndoQ has a relatively relaxed substrate specificity; therefore, the role of EndoQ in restriction modification systems was explored. The activity of the EndoQ homolog from Bacillus subtilis was found not to be inhibited by the uracil glycosylase inhibitor from B. subtilis bacteriophage PBS1, whose genome is completely replaced by uracil instead of thymine. Our findings suggest that EndoQ not only has additional functions in DNA repair but also could act as an antiviral enzyme in organisms with EndoQ. IMPORTANCE Endonuclease Q (EndoQ) is a lesion-specific DNA repair enzyme present in certain bacteria and archaea. To date, it remains unclear how EndoQ recognizes damaged bases. Understanding the mechanism of substrate recognition by EndoQ is important to grasp genome maintenance systems in organisms with EndoQ. Here, we find that EndoQ from the euryarchaeon Pyrococcus furiosus recognizes the imide structure in nucleobases by base flipping, and the cleavage activity is enhanced by the base pair instability of the target base, along with the discovery of its cleavage activity toward 5,6-dihydrouracil, 5-hydroxyuracil, 5-hydroxycytosine, and uridine in DNA. Furthermore, a potential role of EndoQ in Bacillus subtilis as an antiviral enzyme by digesting viral genome is demonstrated.

The Role of the 5'-Hydroxyl Group of Adenosine in Determining Substrate Specificity for Adenosine Deaminase

1967 ◽  
Vol 10 (5) ◽  
pp. 908-912 ◽  
Author(s):  
Alexander. Bloch ◽  
Morris J. Robins ◽  
James R. McCarthy
Keyword(s):  
Substrate Specificity ◽  
Adenosine Deaminase ◽  
Hydroxyl Group
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