A dksA mutant exhibited a defect in induction of RpoS production upon entry into stationary phase Hirsch M, Elliott T,2002 or in the presence of ppGpp Brown L,2002. A dksA mutant exhibited a complex phenotype with respect to ppGpp regulation Brown L,2002. DksA and the general stress response regulator RpoS play a critical role in surviving dehydration. DksA also has an RpoS-independent and ppGpp-related role in dehydration tolerance Chen AI, Goulian M,2018
DksA is implicated in DNA repair; dksA mutants (dksA::kan) show increased sensitivity to compounds - nalidixic acid and mitomycin C - which induce double strand breaks in replicating cells; inactivation of both DksA and RecN significantly reduces the ability of cells to survive chromosome breakage Meddows TR, Savory AP, Grove JI, Moore T, Lloyd RG,2005 DksA plays an active role in the repair of nalidixic acid-induced DNA damage and interaction between DnaK and RNAP is required for this repair Myka KK, Küsters K, Washburn R, Gottesman ME,2019.
A dksA mutant exhibited a defect in amino acid biosynthesis that was suppressed by an rpoB T563P mutation Brown L,2002. A dksA mutation suppressed the replication defect of a plasmid with mutations at the origin of replication Ohkubo S, Yamaguchi K,1997. DksA overproduction suppressed the heat sensitivity of a dnaK or grpE280 mutant Kang PJ,1990. Chandrangsu P,2012. Overproduction also suppressed the heat sensitivity, but not the anucleate cell morphology, of a mukB106 mutant Yamanaka K,1994. Overproduction partially suppressed the filamentous morphology of a dnaK or grpE280 mutant Kang PJ,1990. Overproduction suppressed phenotypes of a prc mutant Bass S, Gu Q, Christen A,1996. Overproduction also suppressed the filamentous morphology and growth defect of a yhhP mutant in low-salt rich medium Ishii Y, Yamada H, Yamashino T, Ohashi K, Katoh E, Shindo H, Yamazaki T, Mizuno T,2000.
DksA regulates the production of inorganic polyphosphate (polyP) without the help of ppGpp Gray MJ,2019 Specifically, dksA positively regulates polyP synthesis upon nutrient limitation Gray MJ,2020. DksA must bind to RNA polymerase to activate polyP synthesis Gray MJ,2020. On the other hand, DksA is required for the formation of new replication origins and constitutive stable DNA replication (cSDR), and it promotes the repair of nalidixic acid (Nal)-induced DNA double-strand breaks (DSBs) Myka KK, Küsters K, Washburn R, Gottesman ME,2019
DksA: dnaK suppressor Kang PJ,1990.
MsmA: multicopy suppressor of mukB106 Yamanaka K,1994.
The crystal structure of DksA has been solved at 2.0 Å resolution, and it shows similarity to the structure of GreA, the transcription cleavage factor Perederina A, Svetlov V, Vassylyeva MN, Tahirov TH, Yokoyama S, Artsimovitch I, Vassylyev DG,2004. On the other hand, the X-ray crystal structures of RNAP has been solved in complex with DksA alone and with ppGpp at 4.5 Å resolution Molodtsov V, Sineva E, Zhang L, Huang X, Cashel M, Ades SE, Murakami KS,2018
Based on overexpression, deletion, transcription profiling, and RNA polymerase mutant experiments, mutual and antagonistic competition effects be...