Premium
The cytotoxin α‐sarcin behaves as a cyclizing ribonuclease
Author(s) -
Lacadena Javier,
Martı́nez del Pozo Alvaro,
Lacadena Valle,
Martı́nez-Ruiz Antonio,
Mancheño José M,
Oñaderra Mercedes,
Gavilanes José G
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00137-9
Subject(s) - ribonuclease , chemistry , biochemistry , rna , gene
The hydrolysis of adenylyl(3′→5′)adenosine (ApA) and guanylyl(3′→5′)adenosine (GpA) dinucleotides by the cytotoxic protein α‐sarcin has been studied. Quantitative analysis of the reaction has been performed through reverse‐phase chromatographic (HPLC) separation of the resulting products. The hydrolysis of the 3′‐5′ phosphodiester bond of these substrates yields the 2′‐3′ cyclic mononucleotide; this intermediate is converted into the corresponding 3′‐monophosphate derivative as the final product of the reaction. The values of the apparent Michaelis constant ( K M ), k cat and k cat / K M have also been calculated. The obtained results fit into a two‐step mechanism for the enzymatic activity of α‐sarcin and allow to consider this protein as a cyclizing RNase.