Unactivated PKR exists in an open conformation capable of binding nucleotides.
AuthorsLemaire PA, Tessmer I, Craig R, Erie DA, Cole JL
JournalBiochemistry
PubMed ID16866353
'The dsRNA-activated protein kinase, PKR, plays a pivotal role in the cellular antiviral response. PKR contains an N-terminal dsRNA binding domain (dsRBD) and a C-terminal kinase domain. An autoinhibition model has been proposed in which latent PKR exists in a closed conformation where the substrate binding cleft of the kinase ... More
Structural and kinetic studies of the 10 S<==>6 S transition in smooth muscle myosin.
AuthorsRosenfeld SS, Xing J, Rener B, Lebowitz J, Kar S, Cheung HC
JournalJ Biol Chem
PubMed ID7982925
The conformational transitions that smooth muscle myosin undergoes after nucleotide binding have been examined using fluorescently labeled nucleotides and regulatory light chain. The 10 S conformation of smooth muscle myosin could be induced by addition of 1-N6-ethenoadenosine or mant ADP plus beryllium fluoride, as well as by mant adenosine 5'-(beta,gamma-iminotriphosphate) ... More
Interactions of Escherichia coli primary replicative helicase DnaB protein with nucleotide cofactors.
AuthorsJezewska MJ, Kim US, Bujalowski W
JournalBiophys J
PubMed ID8889182
Interactions between the Escherichia coli primary replicative helicase DnaB protein and nucleotide cofactors have been studied using several fluorescent nucleotide analogs and unmodified nucleotides. The thermodynamically rigorous fluorescent titration technique has been used to obtain true binding isotherms, independently of the assumptions of any relationships between the observed quenching of ... More
Kinetic mechanism of nucleotide cofactor binding to Escherichia coli replicative helicase DnaB protein. stopped-flow kinetic studies using fluorescent, ribose-, and base-modified nucleotide analogues.
AuthorsBujalowski W, Jezewska MJ
JournalBiochemistry
PubMed ID10684661
The kinetic mechanism of binding nucleotide cofactors to the Escherichia coli primary replicative helicase DnaB protein has been studied, using the fluorescence stopped-flow technique. The experiments have been performed with fluorescent ATP and ADP analogues bearing the modification on the ribose, MANT-AMP-PNP and MANT-ADP, and on the base, epsilonAMP-PNP and ... More
Kinetic mechanism of adenine nucleotide binding to and hydrolysis by the Escherichia coli Rep monomer. 1. Use of fluorescent nucleotide analogues.
AuthorsMoore KJ, Lohman TM
JournalBiochemistry
PubMed ID7981217
The Escherichia coli Rep helicase catalyzes the unwinding of duplex DNA in a reaction that is coupled to ATP binding and hydrolysis. The Rep protein is a stable monomer in the absence of DNA but dimerizes upon binding either single-stranded or duplex DNA, and the dimer appears to be the ... More
Differential inhibition of adenylyl cyclase isoforms and soluble guanylyl cyclase by purine and pyrimidine nucleotides.
AuthorsGille A, Lushington GH, Mou TC, Doughty MB, Johnson RA, Seifert R
JournalJ Biol Chem
PubMed ID14981084
Mammals express nine membranous adenylyl cyclase isoforms (ACs 1-9), a structurally related soluble guanylyl cyclase (sGC) and a soluble AC (sAC). Moreover, Bacillus anthracis and Bacillus pertussis produce the AC toxins, edema factor (EF), and adenylyl cyclase toxin (ACT), respectively. 2'(3')-O-(N-methylanthraniloyl)-guanosine 5'-[gamma-thio]triphosphate is a potent competitive inhibitor of AC in ... More