Binding of transcription termination protein nun to nascent RNA and template DNA.
AuthorsWatnick RS, Gottesman ME
JournalScience
PubMed ID10600743
'The amino-terminal arginine-rich motif of coliphage HK022 Nun binds phage lambda nascent transcript, whereas the carboxyl-terminal domain interacts with RNA polymerase (RNAP) and blocks transcription elongation. RNA binding is inhibited by zinc (Zn2+) and stimulated by Escherichia coli NusA. To study these interactions, the Nun carboxyl terminus was extended by ... More
Translocation of molecules into cells by pH-dependent insertion of a transmembrane helix.
AuthorsReshetnyak YK, Andreev OA, Lehnert U, Engelman DM
JournalProc Natl Acad Sci U S A
PubMed ID16608910
'We have previously observed the spontaneous, pH-dependent insertion of a water-soluble peptide to form a helix across lipid bilayers [Hunt, J. F., Rath, P., Rothschild, K. J. & Engelman, D. M. (1997) Biochemistry 36, 15177-15192]. We now use a related peptide, pH (low) insertion peptide, to translocate cargo molecules attached ... More
Identification of the target of a transcription activator protein by protein-protein photocrosslinking.
AuthorsChen Y, Ebright YW, Ebright RH
JournalScience
PubMed ID8016656
Here it is shown, with the use of protein-protein photocrosslinking, that the carboxyl-terminal region of the alpha subunit of RNA polymerase (RNAP) is in direct physical proximity to the activating region of the catabolite gene activator protein (CAP) in the ternary complex of the lac promoter, RNAP, and CAP. These ... More
S-[2-(4-Azidosalicylamido)ethylthio]-2-thiopyridine (AET) contains a 2-thiopyridyl moiety, which permits cysteine-specific incorporation into protein through a cleavable disulfide bond, and a 4-azidosalicylamido moiety, which permits radioiodination and photoactivatible cross-linking. In contrast to the related compound S-[2-[N-[4-(4-azidosalicylamido)butyl]carbomoyl]ethylthio]-2 -thiopyridine [APDP; Zecherle, G., Oleinikov, A., and Traut, R. (1992) Biochemistry 31, 9526], AET contains a ... More
Mapping of contact sites in complex formation between light-activated rhodopsin and transducin by covalent crosslinking: use of a chemically preactivated reagent.
AuthorsItoh Y, Cai K, Khorana HG
JournalProc Natl Acad Sci U S A
PubMed ID11320238
Contact sites in interaction between light-activated rhodopsin and transducin (T) have been investigated by using a chemically preactivated crosslinking reagent, N-succinimidyl 3-(2-pyridyldithio)propionate. The 3 propionyl-N-succinimidyl group in the reagent was attached by a disulfide exchange reaction to rhodopsin mutants containing single reactive cysteine groups in the cytoplasmic loops. Complex formation ... More
The Escherichia coli PII signal transduction protein regulates the activities of the two-component system transmitter protein NRII by direct interaction with the kinase domain of the transmitter module.
AuthorsPioszak AA, Jiang P, Ninfa AJ
JournalBiochemistry
PubMed ID11063581
The PII signal transduction protein regulates the transcription of nitrogen-regulated genes by controlling the kinase and phosphatase activities of NRII. We used a cross-linking approach to study the interaction of the T-loop of the PII protein with NRII. Cross-linking of PII to NRII required ATP and 2-ketoglutarate, allosteric effectors known ... More
Increased sensitivity of oxidized large isoform of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activase to ADP inhibition is due to an interaction between its carboxyl extension and nucleotide-binding pocket.
AuthorsWang D, Portis AR
JournalJ Biol Chem
PubMed ID16822862
In Arabidopsis, oxidation of the large (46-kDa) isoform activase to form a disulfide bond in the C-terminal extension (C-extension) significantly increases its ADP sensitivity for both ATP hydrolysis and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activation, thereby decreasing both activities at physiological ratios of ADP/ATP. In this study, we demonstrate that the C-extension ... More
Mapping of contact sites in complex formation between transducin and light-activated rhodopsin by covalent crosslinking: use of a photoactivatable reagent.
AuthorsCai K, Itoh Y, Khorana HG
JournalProc Natl Acad Sci U S A
PubMed ID11320237
Interaction of light-activated rhodopsin with transducin (T) is the first event in visual signal transduction. We use covalent crosslinking approaches to map the contact sites in interaction between the two proteins. Here we use a photoactivatable reagent, N-[(2-pyridyldithio)-ethyl], 4-azido salicylamide. The reagent is attached to the SH group of cytoplasmic ... More