In-vivo quantification of electron flow through photosystem I - Cyclic electron transport makes up about 35% in a cyanobacterium.

Photosynthetic electron flow, driven by photosystem I and II, provides chemical energy for carbon fixation. In addition to a linear mode a second cyclic route exists, which only involves photosystem I. The exact contributions of linear and cyclic transport are still a matter of debate.

Two novel heteropolymer-forming proteins maintain the multicellular shape of the cyanobacterium Anabaena sp. PCC 7120.

Polymerizing and filament-forming proteins are instrumental for numerous cellular processes such as cell division and growth. Their function in stabilization and localization of protein complexes and replicons is achieved by a filamentous structure. Known filamentous proteins assemble into homopolymers consisting of single subunits - for example, MreB and FtsZ in bacteria - or heteropolymers that are composed of two subunits, for example, keratin and α/β tubulin in eukaryotes.

Phylogenetic Analyses and GAGA-Motif Binding Studies of BBR/BPC Proteins Lend to Clues in GAGA-Motif Recognition and a Regulatory Role in Brassinosteroid Signaling.

Plant GAGA-motif binding factors are encoded by the BARLEY B RECOMBINANT / BASIC PENTACYSTEINE (BBR/BPC) family, which fulfill indispensable functions in growth and development. BBR/BPC proteins control flower development, size of the stem cell niche and seed development through transcriptional regulation of homeotic transcription factor genes. They are responsible for the context dependent recruitment of Polycomb repressive complexes (PRC) or other repressive proteins to GAGA-motifs, which are contained in Polycomb repressive DNA-elements (PREs).