Expression of Active Subunit of Nitrogenase via Integration into Plant Organelle Genome.

Nitrogen availability is crucial for crop yield with nitrogen fertilizer accounting for a large percentage of farmers' expenses. However, an untimely or excessive application of fertilizer can increase risks of negative environmental effects. These factors, along with the environmental and energy costs of synthesizing nitrogen fertilizer, led us to seek out novel biotechnology-driven approaches to supply nitrogen to plants.

Involvement of the N-terminal B-box domain of Arabidopsis BBX32 protein in interaction with soybean BBX62 protein.

Previous studies have demonstrated that Arabidopsis thaliana BBX32 (AtBBX32) represses light signaling in A. thaliana and that expression of AtBBX32 in soybean increases grain yield in multiple locations and multiyear field trials. The BBX32 protein is a member of the B-box zinc finger family from A.

Protein extraction, fractionation, and purification from cyanobacteria.

This chapter deals with methods of protein extraction from cyanobacterial cells based on work in the circadian model organism Synechococcus elongatus PCC 7942. Some of these techniques have already been used successfully for analysis of circadian rhythms in cyanobacteria, whereas others are heretofore unpublished, but may yield exciting results in the near future.

NMR structure of the pseudo-receiver domain of CikA.

The circadian input kinase (CikA) is a major element of the pathway that provides environmental information to the circadian clock of the cyanobacterium Synechococcus elongatus. CikA is a polypeptide of 754 residues and has three recognizable domains: GAF, histidine protein kinase, and receiver-like. This latter domain of CikA lacks the conserved phospho-accepting aspartyl residue of bona fide receiver domains and is thus a pseudo-receiver (PsR).

Quinone sensing by the circadian input kinase of the cyanobacterial circadian clock.

Circadian rhythms are endogenous cellular programs that time metabolic and behavioral events to occur at optimal times in the daily cycle. Light and dark cycles synchronize the endogenous clock with the external environment through a process called entrainment. Previously, we identified the bacteriophytochrome-like circadian input kinase CikA as a key factor for entraining the clock in the cyanobacterium Synechococcus elongatus PCC 7942.

LdpA: a component of the circadian clock senses redox state of the cell.

The endogenous 24-h (circadian) rhythms exhibited by the cyanobacterium Synechococcus elongatus PCC 7942 and other organisms are entrained by a variety of environmental factors. In cyanobacteria, the mechanism that transduces environmental input signals to the central oscillator of the clock is not known. An earlier study identified ldpA as a gene involved in light-dependent modulation of the circadian period, and a candidate member of a clock-entraining input pathway.