Characterization of two compatible small plasmids from Sphingobium yanoikuyae.

We isolated and characterized two small cryptic indigenous plasmids, pYAN-1 (4,896 bp) and pYAN-2 (4,687 bp), from Sphingobium yanoikuyae, and developed a versatile system that permitted genetic manipulation of the genus Sphingomonas. Nucleotide sequencing of both plasmids revealed that they contained mobA, mobs, and repA genes, which are predicted to encode proteins associated with mobilization and replication, in common. Transformation with each plasmid harboring the antibiotic resistance gene by electroporation was fully successful, using Novosphingobium capsulatum as a host.