L. Romberg | Semantic Scholar

A new assay is reported in which the processive movement of individual fluorescently labelled kinesin molecules along a microtubule can be visualized directly; this observation is achieved by low-background total internal reflection fluorescence microscopy in the absence of attachment of the motor to a cargo (for example, an organelle or bead).

The results indicate that structural features of the neck coiled coil, although not essential for processivity, can tune the efficiency of single molecule motility.

FtsZ polymer stability appears to be fine-tuned such that subtle changes in its assembly kinetics result in large changes in the Z ring structure.

This work has developed a model for the isodesmic polymerization that includes GTP hydrolysis in the scheme and predicts that unlike microtubules, FtsZ protofilaments consist of GTP-bound FTSZ subunits that hydrolyze their nucleotide only slowly and are connected by high affinity longitudinal bonds with a nanomolarK D .

It is suggested that pure FtsZ polymers, unlike microtubules, may not be able to undergo dynamic instability or to store energy in the polymer for force production.

Five structurally diverse compounds are identified, named Zantrins, which inhibit FtsZ GTPase either by destabilizing the FTSZ protofilaments or by inducing filament hyperstability through increased lateral association, illustrating the utility of small-molecule chemical probes to study Ftsz polymerization dynamics and the feasibility of Fts Z as a novel therapeutic target.

A model for cooperative polymerization that does not require polymers to be multistranded is developed that allows subunits in oligomers to associate with high affinity, whereas a lower-affinity conformation is favored in monomers.

The recomLine assay provides a valuable tool for the diagnosis of H. pylori infection and has increased discriminatory power in direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), for the assessment of individual risk for gastrointestinal disease.

Kinesin converts ATP energy into mechanical work by a pathway distinct from that of myosin or dynein when intermediate states in the hydrolysis cycle are prolonged with ATP analogues or inhibitors, implying that all cytoskeletal motors might operate by a common mechanism.