The MinC protein is one of three proteins in the

Min system The Min System is a mechanism composed of three proteins MinC, MinD, and MinE used by ''E. coli'' as a means of properly localizing the septum prior to cell division. Each component participates in generating a dynamic oscillation of FtsZ protei ...

encoded by the ''minB''

operon In genetics, an operon is a functioning unit of DNA containing a cluster of genes under the control of a single promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo splic ...

and which is required to generate pole to pole oscillations prior to bacterial cell division as a means of specifying the midzone of the cell. This function is achieved by preventing the formation of the

divisome The divisome is a protein complex in bacteria that is responsible for cell division, constriction of inner and outer membranes during division, and peptidoglycan (PG) synthesis at the division site. The divisome is a membrane protein complex with ...

Z-ring around the poles.

History

When initially discovered in ''

E.coli ''Escherichia coli'' (),Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. also known as ''E. coli'' (), is a Gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Esche ...

'', MinC was believed to form a stable cap by binding with MinD at the bacterial caps in a stable and static manner, thereby specifying the mid-zone of the cell by lower-concentration or lack of this complex in that region, alleviating inhibition of Z-ring formation. However, Raskin & de Boer applied live-cell imaging with GFP fusion proteins to reveal a dynamic interaction of the Min proteins, demonstrating that MinC and MinD, with the essential help of MinE, actually rapidly oscillate between the two poles in a non-static manner. MinC is found in diverse genera, including

Neisseria ''Neisseria'' is a large genus of bacteria that colonize the mucosal surfaces of many animals. Of the 11 species that colonize humans, only two are pathogens, '' N. meningitidis'' and ''N. gonorrhoeae''. ''Neisseria'' species are Gram-negativ ...

Bacillus ''Bacillus'' (Latin "stick") is a genus of Gram-positive, rod-shaped bacteria, a member of the phylum '' Bacillota'', with 266 named species. The term is also used to describe the shape (rod) of other so-shaped bacteria; and the plural ''Bacill ...

, and

Synechocystis ''Synechocystis'' is a genus of unicellular, freshwater cyanobacteria in the family Merismopediaceae. It includes a strain, ''Synechocystis'' sp. PCC 6803, which is a well studied model organism. Like all cyanobacteria, ''Synechocystis'' ...

, but is absent in an equally wide assortment of genera (e.g. Caulobacter, Mycobacterium). Many bacteria that lack MinC carry alternative proteins that can position their Z-ring.

Function

MinC is known to dimerize and functions as an

FtsZ FtsZ is a protein encoded by the ''ftsZ'' gene that assembles into a ring at the future site of bacterial cell division (also called the Z ring). FtsZ is a prokaryotic homologue of the eukaryotic protein tubulin. The initials FtsZ mean "Filam ...

protein inhibitor, antagonizing its structure assembly when in a high enough concentration. The protein has the ability to disassemble the ZapA, ZapB and ZipA proteins which preferentially bind to the FtsZ scaffold protein and which are needed to initiate cell division. Concentrations of MinC are lowest at the mid-zone of bacterial cells, thereby permitting septum formation and scaffold assembly at the cellular mid-zone since the Min System proteins (MinCDE) are lowest in concentration in this region, alleviating the physical inhibition on the proteins required to initiate division.

References

{{Reflist Bacterial proteins