Open AccessReversibility of the Pyrophosphoryl Transfer from ATP to GTP by Escherichia coli Stringent Factor
Author(s) -
José Sy
Publication year - 1974
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.71.9.3470
Subject(s) - chemistry , guanosine , guanosine triphosphate , gtp' , adenosine triphosphate , ef tu , escherichia coli , guanosine diphosphate , adenosine diphosphate , biochemistry , ribosome , enzyme , rna , biology , gene , platelet , platelet aggregation , immunology
The stringent factor-catalyzed, ribosome-dependent synthesis of guanosine polyphosphates is found to be reversible. The reverse reaction specifically requires 5′-AMP as the pyrophosphoryl acceptor, and guanosine 5′-triphosphate-3′-diphosphate is preferentially utilized as the pyrophosphoryl donor. The primary products of the reaction are GTP and ATP. The reverse reaction is strongly inhibited by the antibiotics thiostrepton and tetracycline, and by ATP and β-γ-methylene-adenosine-triphosphate, but not by ADP, GTP, and GDP. The reverse reaction occurs under conditions for nonribosomal synthesis. The overall reaction for stringent factor-catalyzed guanosine polyphosphate formation may thus be formulated: (p)pp5′G + ppp5′A ⇌ (p)pp5′G3′pp + p5′A.