A probable RNA chaperone. Forms a complex with KhpA which binds to cellular RNA and controls its expression. Plays a role in peptidoglycan (PG) homeostasis and cell length regulation. Forms a complex with KhpA which stimulates or controls elongasome-mediated lateral cell wall biosynthesis (PubMed:30842445). RNA-bonding protein; overexpression leads to cell elongation, suggesting it plays a role in cell division and maintenance of cell shape (PubMed:27776484). In cell elongation the phosphorylated form activates cell elongation while the non-phosphorylated form is less active or inactive (Probable). Probably plays a role in regulation of other RNAs (By similarity). Interacts with StkP which phosphorylates it (PubMed:27776484, PubMed:28710862). Interacts with KhpA via the KH domain of this protein (PubMed:30842445). Interacts with MreC in the elongasome (PubMed:28710862). Interacts with MltG, RodZ and YidC2, interacts with MltG's N-terminus (PubMed:33558392). Localizes to midcell in the septal area; some protein remains in the cytoplasm. Has an N-terminal Jag-N, a linker with a phosphorylated Thr, and 2 RNA-binding domains (KH and R3H) (Probable). A phosphomimetic mutation and mutations that prevent nucleic acid binding are not tolerated in strain R6 (PubMed:28710862). The KH domain of this protein interacts with KhpA (PubMed:30842445). The Jag-N domain is responsible for targeting to the midcell (PubMed:33558392). Phosphorylated on Thr-89 by StkP; there is another phosphorylated Thr residue in the protein, which is more strongly phosphorylated in strain R6 than in Rx1 (PubMed:27776484, PubMed:28710862). Dephosphorylated by PhpP (PubMed:27776484). Phosphorylation is increased in an R6 strain with a C-terminal MreC deletion (PubMed:28710862). Grows more slowly with a longer lag phase and decreased final density compared to wild-type. Cells are significantly smaller (PubMed:27776484, PubMed:28710862). Suppresses deletions of PBP2b (penA). Double penA-khpB or rodA-khpB deletions partially alleviate the slow growth phenotype of the single deletion (PubMed:28710862). KhpA is no longer targeted to midcell (PubMed:30842445). Strain Rx1 is unencapsulated. Belongs to the KhpB RNA-binding protein family.