AUTHOR=Riber Leise , Koch Birgit M. , Kruse Line Riis , Germain Elsa , Løbner-Olesen Anders 

TITLE=HipA-Mediated Phosphorylation of SeqA Does not Affect Replication Initiation in Escherichia coli

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.02637

DOI=10.3389/fmicb.2018.02637

ISSN=1664-302X

ABSTRACT=<p>The SeqA protein of <italic>Escherichia coli</italic> is required to prevent immediate re-initiation of chromosome replication from <italic>oriC</italic>. The SeqA protein is phosphorylated at the serine-36 (Ser36) residue by the HipA kinase. The role of phosphorylation was addressed by mutating the Ser36 residue to alanine, which cannot be phosphorylated and to aspartic acid, which mimics a phosphorylated serine residue. Both mutant strains were similar to wild-type with respect to origin concentration and initiation synchrony. The minimal time between successive initiations was also unchanged. We therefore suggest that SeqA phosphorylation at the Ser36 residue is silent, at least with respect to SeqA's role in replication initiation.</p>