Asymmetric amino acid activation by class II histidyl-tRNA synthetase from Escherichia coli.
AuthorsGuth E, Farris M, Bovee M, Francklyn CS,
JournalJ Biol Chem
PubMed ID19487703
'Aminoacyl-tRNA synthetases (ARSs) join amino acids to their cognate tRNAs to initiate protein synthesis. Class II ARS possess a unique catalytic domain fold, possess active site signature sequences, and are dimers or tetramers. The dimeric class I enzymes, notably TyrRS, exhibit half-of-sites reactivity, but its mechanistic basis is unclear. In ... More
Quantum dot-based multiplexed fluorescence resonance energy transfer.
AuthorsClapp AR, Medintz IL, Uyeda HT, Fisher BR, Goldman ER, Bawendi MG, Mattoussi H
JournalJ Am Chem Soc
PubMed ID16366574
We demonstrate the use of luminescent quantum dots (QDs) conjugated to dye-labeled protein acceptors for nonradiative energy transfer in a multiplexed format. Two configurations were explored: (1) a single color QD interacting with multiple distinct acceptors and (2) multiple donor populations interacting with one type of acceptor. In both cases, ... More
Visualizing the distribution and transport of mRNAs in living cells.
AuthorsBratu DP, Cha BJ, Mhlanga MM, Kramer FR, Tyagi S
JournalProc Natl Acad Sci U S A
PubMed ID14583593
We have visualized the movements of native mRNAs in living cells. Using nuclease-resistant molecular beacons, we imaged the transport and localization of oskar mRNA in Drosophila melanogaster oocytes. When the localization pattern was altered by genetic manipulation of the mRNA's 3' untranslated region, or by chemical perturbation of the intracellular ... More
Resonance energy transfer for assessing the molecular integrity of proteins for local delivery.
AuthorsWu D, Edelman ER
JournalBiotechnol Bioeng
PubMed ID14755558
It remains unclear whether the limitations to the therapeutic potential of angiogenic growth factors stem from pharmacokinetic concerns related to inadequate delivery or from a reduced sensitivity of target tissues. Here, we report a novel method using resonance energy transfer to assess the molecular integrity of proteins after local delivery. ... More
Docking and rolling, a model of how the mitotic motor Eg5 works.
AuthorsRosenfeld SS, Xing J, Jefferson GM, King PH
JournalJ Biol Chem
PubMed ID16115880
Whereas kinesin I is designed to transport cargoes long distances in isolation, a closely related kinesin motor, Eg5, is designed to generate a sustained opposing force necessary for proper mitotic spindle formation. Do the very different roles for these evolutionarily related motors translate into differences in how they generate movement? ... More
Binding of the b-subunit in the ATP synthase from Escherichia coli.
AuthorsDiez M, Börsch M, Zimmermann B, Turina P, Dunn SD, Gräber P
JournalBiochemistry
PubMed ID14744151
The rotary mechanism of ATP synthase requires a strong binding within stator subunits. In this work we studied the binding affinity of the b-subunit to F(1)-ATPase of Escherichia coli. The dimerization of the truncated b-subunit without amino acids 1-33, b(34-156)T62C, was investigated by analytical ultracentrifugation, resulting in a dissociation constant ... More