Microbiology Comment

Cyanophycin Modifications—Widening the Application Potential

“…Then, the next aspartic acid is bound by peptide bond to the C-terminus of the backbone. Next, the γ-carboxylic acid is activated by phosphorylation and arginine is attached at this position by an isopeptide bond ( Forchhammer and Watzer, 2016 ; Frommeyer et al, 2016 ; Du et al, 2019 ).…”

Cyanophycin and its biosynthesis: not hot but very cool

“…CphA2 is found in unicellular and multicellular diazotrophic cyanobacteria that also encode CphA1, suggesting that the two enzymes play complementary roles. 14,134 Knockout experiments showed that under N 2 -xing conditions DcphA2 cells accumulated 10-20% less cyanophycin 14,133 and displayed impaired growth. 14 In Anabaena sp.…”

“…73 The ability to separately control the relative CphA1 and CphA2 expression within a single cell, as well as differentially between cell types or based on position in a lament, provide cyanobacteria with mechanisms to control the balance between cyanophycin production and degradation. 14,134 This could allow an advantageous ne-tuning of their arginine and aspartate budget and the amount of nitrogen that ows into primary metabolic processes. 134 Our recent structures 135,136 revealed two distinct architectures for CphA2.…”

“…14,134 This could allow an advantageous ne-tuning of their arginine and aspartate budget and the amount of nitrogen that ows into primary metabolic processes. 134 Our recent structures 135,136 revealed two distinct architectures for CphA2. Of 9 enzymes we characterized biochemically, most exist as dimers, 14,135 but one is hexameric (Figs.…”

Sunlight-driven recycling to increase nutrient use-efficiency in agriculture

“…As an example, in cyanobacteria, N can be stored in the form of cyanophycin granule polypeptides (CGP), a co-polymer of aspartate and arginine, whose synthesis depends on a single enzyme, cyanophycin synthetase (CPHA1), catalysing a two-steps reaction (i.e. aspartate ligation and consequently an arginine ligation [74,75]). Many cyanobacteria but also eukaryotic microalgae species also have a significant capability to accumulate proteins, up to 70% dry weight [76,77] in some conditions, which might represent a complementary luxury overaccumulation strategy.…”