**4. Conclusions**

The PhoD-like enzyme gene was firstly isolated from the marine bacterium *Cobetia amphilecti* KMM 296 and cloned into *E.coli*. The effects of chemicals, metal ions, kinetic parameters, and substrate specificity on the enzymatically active recombinant product, CamPhoD, expressed from this gene confirmed that the enzyme carries a metabolic function of phosphatase/phosphodiesterase of the PhoD family in the marine environment. The enzyme bimetal dependence coincides with the modeling results for the enzymatic complex, with phosphate in the active center surrounded by two Co2<sup>+</sup> ions and one Fe3<sup>+</sup> ion. This enzyme of marine origin has been concluded to be a new member of the bifunctional PhoD-like phosphatase/phosphodiesterase class, with a characteristic structure and important biological functions.

**Author Contributions:** Conceptualization, L.B. and L.T.; methodology, Y.N. and N.T.; software, G.L.; validation, L.B.; investigation, Y.N. and N.T.; resources, L.T. and O.S.; data curation, L.B.; writing—original draft preparation, Y.N.; writing—review and editing, L.B.

**Funding:** This research was funded by the program of RAS, grant number 18-4-051.

**Conflicts of Interest:** The authors declare no conflict of interest.
