Haloferax mediterranei GlnK proteins are post-translationally modified by uridylylation


Correspondence: Professor Dr. María José Bonete, Departamento de Agroquímica y Bioquímica, Facultad de Ciencias, Universidad de Alicante, carretera de San Vicente s/n, 03080 Alicante, Spain

E-mail: mjbonete@ua.es

Fax: +34 965 90 9955/3524


In this work we report for the first time a post-translational modification of PII homologues from the Archaea Domain. Haloferax mediterranei is the first haloarchaea whose PII proteins have been studied, it possesses two of them (GlnK1 and GlnK2), both encoded adjacent to a gene for the ammonia transporter Amt. An approach based on 2DE, anti-GlnK immunoblot and peptide mass fingerprint (MALDI-TOF-MS) of the reactive spots showed that GlnK proteins in H. mediterranei are post-translationally uridylylated. A third spot with lower pI suggests the existence of a non-descript post-translational modification in this protein family.