Premium
A microcin processing peptidase‐like protein of the cyanobacterium Synechococcus elongatus is essential for secretion of biofilm‐promoting proteins
Author(s) -
Parnasa Rami,
Sendersky Eleonora,
Simkovsky Ryan,
Waldman BenAsher Hiba,
Golden Susan S.,
Schwarz Rakefet
Publication year - 2019
Publication title -
environmental microbiology reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.229
H-Index - 69
ISSN - 1758-2229
DOI - 10.1111/1758-2229.12751
Subject(s) - periplasmic space , biofilm , secretion , secretory protein , mutant , biology , biochemistry , synechococcus , microbiology and biotechnology , gene , chemistry , cyanobacteria , escherichia coli , bacteria , genetics
Summary Small secreted compounds, e.g. microcins, are characterized by a double‐glycine (GG) secretion motif that is cleaved off upon maturation. Genomic analysis suggests that small proteins that possess a GG motif are widespread in cyanobacteria; however, the roles of these proteins are largely unknown. Using a biofilm‐proficient mutant of the cyanobacterium Synechococcus elongatus PCC 7942 in which the constitutive biofilm self‐suppression mechanism is inactivated, we previously demonstrated that four small proteins, E nable b iofilm f ormation with a G G motif (EbfG1‐4), each with a GG motif, enable biofilm formation. Furthermore, a peptidase belonging to the C39 family, P eptidase t ransporter e nabling B iofilm (PteB), is required for secretion of these proteins. Here, we show that the microcin processing peptidase‐like protein encoded by gene Synpcc7942_1127 is also required for biofilm development – inactivation of this gene in the biofilm‐proficient mutant abrogates biofilm development. Additionally, this peptidase‐like protein (denoted EbfE – enables biofilm formation peptidase) is required for secretion of the EbfG biofilm‐promoting small proteins. Given their protein‐domain characteristics, we suggest that PteB and EbfE take part in a maturation‐secretion system, with PteB being located to the cell membrane while EbfE is directed to the periplasmic space via its secretion signal.