*Article* **Genome-Wide Analysis of PL7 Alginate Lyases in the Genus** *Zobellia*

**Nadezhda Chernysheva, Evgeniya Bystritskaya, Galina Likhatskaya , Olga Nedashkovskaya and Marina Isaeva \***

G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, 690022 Vladivostok, Russia; chernysheva.nadezhda@gmail.com (N.C.); belyjane@gmail.com (E.B.); galin56@mail.ru (G.L.); oned2004@mail.ru (O.N.)

**\*** Correspondence: issaeva@gmail.com; Tel.: +7-423-231-1168

**Abstract:** We carried out a detailed investigation of PL7 alginate lyases across the *Zobellia* genus. The main findings were obtained using the methods of comparative genomics and spatial structure modeling, as well as a phylogenomic approach. Initially, in order to elucidate the alginolytic potential of *Zobellia*, we calculated the content of polysaccharide lyase (PL) genes in each genome. The genusspecific PLs were PL1, PL6, PL7 (the most abundant), PL14, PL17, and PL40. We revealed that PL7 belongs to subfamilies 3, 5, and 6. They may be involved in local and horizontal gene transfer and gene duplication processes. Most likely, an individual evolution of PL7 genes promotes the genetic variability of the Alginate Utilization System across *Zobellia*. Apparently, the PL7 alginate lyases may acquire a sub-functionalization due to diversification between in-paralogs.

**Keywords:** *Zobellia*; genomes; polysaccharide lyase family 7; alginate utilization system; paralogs; orthologs
