A Moonlighting Enzyme Links Escherichia coli Cell Size with Central Metabolism

Abstract

Growth rate and nutrient availability are the primary determinants of size in single-celled organisms: rapidly growing Escherichia coli cells are more than twice as large as their slow growing counterparts. Here we report the identification of the glucosyltransferase OpgH as a nutrient-dependent regulator of E. coli cell size. During growth under nutrient-rich conditions, OpgH localizes to the nascent septal site, where it antagonizes assembly of the tubulin-like cell division protein FtsZ, delaying division and increasing cell size. Biochemical analysis is consistent with OpgH sequestering FtsZ from growing polymers. OpgH is functionally analogous to UgtP, a Bacillus subtilis glucosyltransferase that inhibits cell division in a growth rate-dependent fashion. In a striking example of convergent evolution, OpgH and UgtP share no homology, have distinct enzymatic activities, and appear to inhibit FtsZ assembly through different mechanisms. Comparative analysis of E. coli and B. subtilis reveals conserved aspects of growth rate regulation and cell size control that are likely to be broadly applicable. These include the conservation of uridine diphosphate glucose as a proxy for nutrient status and the use of moonlighting enzymes to couple growth rate-dependent phenomena to central metabolism.

Evidence That Bacteriophage λ Kil Peptide Inhibits Bacterial Cell Division by Disrupting FtsZ Protofilaments and Sequestering Protein Subunits

“…Such an increase in the critical concentration is a hallmark of sequestration and was previously described for other inhibitors like SulA and OpgH (29,30). Interestingly, calculation of an apparent K d value for the binding of Kil to FtsZ from the shift in the apparent critical concentration, according to a model in which it is assumed that the inhibition occurs through sequestration (see Equation 6 in Ref.…”

“…Other negative regulators of FtsZ assembly in E. coli include the SOS response factor SulA (26); YeeV and the membrane protein CptA (YgfX), both considered part of toxin-antitoxin systems (27,28); and OpgH, a moonlighting enzyme that delays division increasing cell size (29). In contrast to MinC and SlmA, most of these proteins antagonize FtsZ polymerization through a sequestration mechanism entailing significant reduction of the rate at which GTP is hydrolyzed by FtsZ (28 -30).…”

Toward the assembly of a minimal divisome

“…Cell division is intimately related to growth (Hill et al 2013) and genome replication. Mechanisms ensuring that cells grow to the right size and the genome duplicates work in concert with the division machinery.…”

A surprising range of modified-methionyl S-adenosylmethionine analogues support bacterial growth

“…This may reflect the known role of D-amino acids in modulating peptidoglycan structure in some bacteria (Lam et al, 2009), and the possible association of altered peptidoglycan with formation of minicells (Obermann & Höltje, 1994). In addition, a number of cell stresses and environments can affect E. coli morphology (Darmon et al, 2014;Hill et al, 2013). In this respect, while not affecting comparison of MOB1490 cells in the presence of different AdoMet analogues, it is noteworthy that the MOB1490 cells tended to be longer than those of the parental strain PS2209 even in the presence of 32 mM AdoMet (Fig.…”