The concept of RNA-assisted protein folding: the role of tRNA

We suggest that tRNA actively participates in the transfer of 3D information from mRNA to peptides - in addition to its well-known, "classical" role of translating the 3-letter RNA codes into the one letter protein code. The tRNA molecule displays a series of thermodynamically favored configurations during translation, a movement which places the codon and coded amino acids in proximity to each other and make physical contact between some amino acids and their codons possible. This specific codon-amino acid interaction of some selected amino acids is necessary for the transfer of spatial information from mRNA to coded proteins, and is known as RNA-assisted protein folding

Models of classroom assessment for course-based research experiences

Course-based research pedagogy involves positioning students as contributors to authentic research projects as part of an engaging educational experience that promotes their learning and persistence in science. To develop a model for assessing and grading students engaged in this type of learning experience, the assessment aims and practices of a community of experienced course-based research instructors were collected and analyzed. This approach defines four aims of course-based research assessment—(1) Assessing Laboratory Work and Scientific Thinking; (2) Evaluating Mastery of Concepts, Quantitative Thinking and Skills; (3) Appraising Forms of Scientific Communication; and (4) Metacognition of Learning—along with a set of practices for each aim. These aims and practices of assessment were then integrated with previously developed models of course-based research instruction to reveal an assessment program in which instructors provide extensive feedback to support productive student engagement in research while grading those aspects of research that are necessary for the student to succeed. Assessment conducted in this way delicately balances the need to facilitate students’ ongoing research with the requirement of a final grade without undercutting the important aims of a CRE education

Controlling the Conflict of Interest in Management Buyouts.

A controversial aspect of the management buyouts that were popular throughout the 1980s is the potential for a conflict of interest to arise when a manager bids to acquire the firm he manages. This study examines 184 management buyouts and reports three findings. First, returns to prebuyout shareholders are greater when managers must bid against outside acquirers. Second, bid revisions in the face of competition exceed revisions due to shareholder litigation and negotiations with boards. Third, the incidence of competition is negatively related to the prebuyout share holdings of managers. Coauthors are Ronald F. Singer, Anju Seth, and Darla F. Lang. Copyright 1994 by MIT Press.

Ribonuclease P RNA: Models of the 15/16 Bulge From Escherichia Coli and the P15 Stem Loop of Bacillus Subtilis

©1997 RNA Society. Published by Cold Spring Harbor LaboratoryThe Escherichia coli ribonuclease P RNA 15/16 internal bulge loop and the Bacillus subtilis P15 stem loop are important substrate binding sites for the CCA-3' terminus of pre-tRNA. Models of E. coli 15/16 bulge loop and the B. subtilis P15 stem loop have been constructed using MC-SYM, a constraint satisfaction program. The models use covariation analysis data for suggesting initial base pairings, chemical probing, and protection/modification results to determine particular pairing orientations, and mutational experimental analysis data for tRNA-RNase P RNA contacts. The structures from E. coli and B. subtilis, although different _in secondary structure, have similar sequence and function. Using MC-SYM, we are able to illustrate how the 3' end of the pre-tRNA is able to interact with this segment of the catalytic RNase P RNA. In addition, we propose additional hydrogen bonding between A76 in the 3' terminus of the tRNA and the 15/16 region of E. coli and to the loop of B. subtilis

Modeling the structure of the ribosome

© 1995 NRC Canada. The definitive version is available online at: http://pubs.nrc-cnrc.gc.caConsidering the size and complexity of the ribosome and the growing body of data from a wide range of experiments on ribosomal structure, it is becoming increasingly important to develop tools that facilitate the development of reliable models for the ribosome. We use a combination of manual and computer-based approaches for building and refining models of the ribosome and other RNA–protein complexes. Our methods are aimed at determining the range of models compatible with the data, making quantitative statements about the positional uncertainties (resolution) of different regions, identifying conflicts in the data, establishing which regions of the ribosome need further experimental exploration, and, where possible, predicting the outcome of future experiments. Our previous low-resolution model for the small subunit of the Escherichia coli ribosome is briefly reviewed, along with progress on atomic resolution modeling of the mRNA–tRNA complex and its interaction with the decoding site of the 16S RNA