CyDiv, a Conserved and Novel Filamentous Cyanobacterial Cell Division Protein Involved in Septum Localization

Abstract

Cell division in bacteria has been studied mostly in Escherichia coli and Bacillus subtilis, model organisms for Gram-negative and Gram-positive bacteria, respectively. However, cell division in filamentous cyanobacteria is poorly understood. Here, we identified a novel protein, named CyDiv (Cyanobacterial Division), encoded by the all2320 gene in Anabaena sp. PCC 7120. We show that CyDiv plays a key role during cell division. CyDiv has been previously described only as an exclusive and conserved hypothetical protein in filamentous cyanobacteria. Using polyclonal antibodies against CyDiv, we showed that it localizes at different positions depending on cell division timing: poles, septum, in both daughter cells, but also in only one of the daughter cells. The partial deletion of CyDiv gene generates partial defects in cell division, including severe membrane instability and anomalous septum localization during late division. The inability to complete knock out CyDiv strains suggests that it is an essential gene. In silico structural protein analyses and our experimental results suggest that CyDiv is an FtsB/DivIC-like protein, and could therefore, be part of an essential late divisome complex in Anabaena sp. PCC 7120.

The multicellular nature of filamentous heterocyst-forming cyanobacteria

“…More recently, FtsW has been proposed to be a divisome-linked peptidoglycan glycosyltransferase (Meeske et al 2016). Importantly, however, Anabaena appears to lack FtsB, FtsL and FtsN (although recently a protein structurally similar to FtsB has been named CyDiv and claimed to represent an FtsB analog; Mandakovic et al 2016). FtsQ, FtsB and FtsL are conserved together in many bacteria with diverse shapes and cell-division modes (González et al 2010).…”

Genetic Modification of Cyanobacteria by Conjugation Using the CyanoGate Modular Cloning Toolkit

“…Prior to conjugation, validation of finalized Level T vectors by restriction digest and PCR is recommended. Conjugal DNA transfer is a well stablished technique for cyanobacterial strains, including those that are not naturally transformable 41,45 . Important steps in the conjugation protocol include: 1) careful handling of the helper E. coli strain following overnight growth (e.g., avoid vortexing) 35 , 2) taking care to completely remove traces of the antibiotics used to grow helper and cargo E. coli strains, 3) an appropriate incubation period for the mixture of cargo and helper strains and cyanobacteria (e.g., a longer incubation period was critical for S. elongatus UTEX 2973), and 4) the initial transfer period of the cell mixture on membranes in LB-BG11 agar plates lacking antibiotics for 24 h.…”

“…For example, efficient conjugal transfer in Anabaena sp. PCC 7120 requires a helper vector that protects the mobilizer vector against digestion (e.g., pRL623, which encodes for the three methylases AvaiM, Eco47iiM and Ecot22iM) 45,46 .…”

Emerging Species and Genome Editing Tools: Future Prospects in Cyanobacterial Synthetic Biology

“…If present, the efficiency of DNA uptake can be improved by selecting for strains where endonucleases have been inactivated [48]. Otherwise specific methylases, restriction inhibitors and liposomes could be employed during delivery [50,51,52,53].…”