LPS-Dephosphorylating Alkaline Phosphatase of PhoA Family Divergent from the Multiple Homologues of Spp

A highly active alkaline phosphatase (ALP) of the protein structural family PhoA, from a mussel gut-associated strain of the marine bacterium KMM 296 (CmAP), was found to effectively dephosphorylate lipopolysaccharides (LPS). Therefore, the aim of this work was to perform a comprehensive bioinformatics analysis of the structure, and to suggest the physiological role of this enzyme in marine bacteria of the genus . A scrutiny of the CmAP-like sequences in 36 available genomes revealed nine homologues intrinsic to the subspecies , whereas PhoA of a distant relative JO1 carried an inactive mutation. However, phylogenetic analysis of all available ALP sequences showed that each strain of the genus possesses several ALP variants, mostly the genes encoding for PhoD and PhoX families. The strains have a complete set of four ALP families' genes, namely: PhoA, PafA, PhoX, and two PhoD structures. The species is distinguished by the presence of only three PhoX and PhoD genes. The PhoA proteins are clustered together with the human and squid LPS-detoxifying enzymes. In addition, the predicted PhoA biosynthesis gene cluster suggests its involvement in the control of cellular redox balance, homeostasis, and cell cycle. Apparently, the variety of ALPs in spp. indicates significant adaptability to phosphorus-replete and depleted environments and a notable organophosphate destructor in eco-niches from which they once emerged, including spp. The ALP clusterization and degree of similarity of the genus-specific biosynthetic genes encoding for ectoine and polyketide cluster T1PKS, responsible for sulfated extracellular polysaccharide synthesis, coincide with a new whole genome-based taxonomic classification of the genus . The strains and their ALPs are suggested to be adaptable for use in agriculture, biotechnology and biomedicine.