A Quick Primer in Fluorescence-Based Equilibrium and Pre-steady State Methods for Determining Protein-Nucleotide Affinities.

Biomolecular interactions facilitate the biochemical processes that sustain life. Proteins, RNAs, and ribonucleoprotein complexes perform cellular functions that range from catalyzing the formation or cleavage of bonds to being structural building blocks, both of which are only possible through the interaction with their respective biomolecular partner(s). Having access to the parameters that describe these interactions is important for our understanding of the principles that underlie enzymatic and nonenzymatic processes.

Cellular roles of the human Obg-like ATPase 1 (hOLA1) and its YchF homologs.

P-loop NTPases comprise one of the major superfamilies of nucleotide binding proteins, which mediate a variety of cellular processes, such as mRNA translation, signal transduction, cell motility, and growth regulation. In this review, we discuss the structure and function of two members of the ancient Obg-related family of P-loop GTPases: human Obg-like ATPase 1 (hOLA1), and its bacterial/plant homolog, YchF. After a brief discussion of nucleotide binding proteins in general and the classification of the Obg-related family in particular, we discuss the sequence and structural features of YchF and hOLA1.

Introducing a class of standardized and interchangeable parts utilizing programmed ribosomal frameshifts for synthetic biology applications.

Synthetic biology and the rational design of biological devices depend on the availability of standardized and interchangeable biological parts with diverse range of functions. Reliable access to different reading frames during translation has largely been overlooked as functionality for bioengineering applications. Here we report the construction and initial characterization of the first member of such a class of biological parts that conforms to the BioBrick Standard (RFC25), allowing its interchangeable use in biological devices.

The conserved GTPase HflX is a ribosome splitting factor that binds to the E-site of the bacterial ribosome.

Using a combination of biochemical, structural probing and rapid kinetics techniques we reveal for the first time that the universally conserved translational GTPase (trGTPase) HflX binds to the E-site of the 70S ribosome and that its GTPase activity is modulated by peptidyl transferase centre (PTC) and peptide exit tunnel (PET) binding antibiotics, suggesting a previously undescribed mode of action for these antibiotics. Our rapid kinetics studies reveal that HflX functions as a ribosome splitting factor that disassembles the 70S ribosomes into its subunits in a nucleotide dependent manner. Furthermore, our probing and hydrolysis studies show that the ribosome is able to activate trGTPases bound to its E-site.

The ribosome modulates the structural dynamics of the conserved GTPase HflX and triggers tight nucleotide binding.

The universally conserved GTPase HflX is a putative translation factor whose GTPase activity is stimulated by the 70S ribosome as well as the 50S but not the 30S ribosomal subunit. However, the details and mechanisms governing this interaction are only poorly understood. In an effort to further elucidate the functional mechanism of HflX, we examined its interaction with the 70S ribosome, the two ribosomal subunits (50S and 30S), as well as its ability to interact with guanine nucleotides in the respective ribosomal complexes using a highly purified in vitro system.