Biochemistry, Biophysics, and Structural Biology Commons^™

Two Distinct Modes Of Metal Ion Binding In The Nuclease Active Site Of A Viral Dna-Packaging Terminase: Insight Into The Two-Metal-Ion Catalytic Mechanism, Haiyan Zhao, Zihan Lin, Anna Y. Lynn, Brittany Varnado, John A. Beutler, Ryan P. Murelli, Stuart F.J. Le Grice, Liang Tang

Publications and Research

Many dsDNA viruses encode DNA-packaging terminases, each containing a nuclease domain that resolves concatemeric DNA into genome-length units. Terminase nucleases resemble the RNase H-superfamily nucleotidyltransferases in folds, and share a two-metal-ion catalytic mechanism. Here we show that residue K428 of a bacteriophage terminase gp2 nuclease domain mediates binding of the metal cofactor Mg2+. A K428A mutation allows visualization, at high resolution, of a metal ion binding mode with a coupled-octahedral configuration at the active site, exhibiting an unusually short metal-metal distance of 2.42 A° . Such proximity of the two metal ions may play an essential role in catalysis by …

Incipient Speciation In Freshwater Fish Species From Two Isolated Watersheds, Paula Gore Miller

Dissertations, Theses, and Capstone Projects

The process of speciation occurs as a result of restricted gene flow between segments of an interbreeding population occupying different geographic areas. This separation may result in isolated populations which undergo genetic and phenotypic changes. The Wisconsin glacial period, which ended approximately 17,500 years ago, dramatically altered the geography of North America. The glacier covered almost the entire North America as it advanced. Areas that were not covered with ice provided suitable habitats (refugia) for relict species that were previously widespread in the northern section of the continent. As the ice sheet retreated, animals and plants were able to return …

Protein Sectors: Statistical Coupling Analysis Versus Conservation, Tiberiu Teşileanu, Lucy J. Colwell, Stanislas Leibler

Publications and Research

Statistical coupling analysis (SCA) is a method for analyzing multiple sequence alignments that was used to identify groups of coevolving residues termed “sectors”. The method applies spectral analysis to a matrix obtained by combining correlation information with sequence conservation. It has been asserted that the protein sectors identified by SCA are functionally significant, with different sectors controlling different biochemical properties of the protein. Here we reconsider the available experimental data and note that it involves almost exclusively proteins with a single sector. We show that in this case sequence conservation is the dominating factor in SCA, and can alone be …

Functional Characterization Of The Plant 15-Cis-Zeta-Carotene Isomerase Z-Iso, Jesus Alonso Beltran Zambrano

Dissertations, Theses, and Capstone Projects

Vitamin A deficiency is a widespread health issue in the tropics. To solve this issue, efforts are underway to increase provitamin A carotenoids such as β-carotene in staple crops which can be achieved by breeding, metabolic engineering or a combination of both approaches. However, rational strategies to improve carotenoid content in crops require sufficient knowledge of pathway regulation. Therefore, to better understand how plants synthesize provitamin A and to guide metabolic engineering strategies in crops such as maize, the functional characterization of the new ζ-carotene isomerase (Z-ISO) is of significant importance.

Z-ISO was recently discovered in maize and Arabidopsis (Chen …

Human Anatomy And Physiology Preparatory Course (1st Edition), Carlos Liachovitzky

Open Educational Resources

The overall purpose of this preparatory course textbook is to help students familiarize with some terms and some basic concepts they will find later in the Human Anatomy and Physiology I course.

The organization and functioning of the human organism generally is discussed in terms of different levels of increasing complexity, from the smallest building blocks to the entire body. This Anatomy and Physiology preparatory course covers the foundations on the chemical level, and a basic introduction to cellular level, organ level, and organ system levels. There is also an introduction to homeostasis at the beginning.