Nucleic acid-binding properties of the P1 protein of turnip mosaic potyvirus produced in Escherichia coli

Abstract

The N-terminal P1 protein of tumip mosaic potyvirus (TuMV) polyprotein was overexpressed in Escherichia coli, purified by metal chelation chromatography under denaturing conditions and renatured. U.v. cross-linking experiments indicated that the recombinant protein interacted with RNA, and gel retardation electrophoresis demonstrated that more than one molecule of P1 bound one molecule of RNA. Formation of the protein-RNA complexes was dependent on the conformational state of P1 and was stable at relatively high concentrations of NaCI. P1 had the ability to bind ssRNA and ssDNA, with similar affinity, but was not able to bind to dsDNA. The TuMV protein had the additional characteristic of binding dsRNA with affinity similar to that observed with single-stranded nucleic acids.

VPg, coat protein and five non-structural proteins of potato A potyvirus bind RNA in a sequence-unspecific manner.

“…In contrast, no RNA-binding activity was observed with P3. Our findings on P1, HC-Pro, CI and NIaPro of PVA were consistent with previously published data for the corresponding proteins of other potyviruses (Brantley & Hunt, 1993 ;Soumounou & Laliberte, 1994 ;Maia & Bernardi, 1996 ;Eagles et al, 1994 ;Ferna! ndez et al, 1995 ;Daro' s & Carrington, 1997).…”

“…In all these processes, interaction(s) between viral genomic RNA and viral protein(s) may play a crucial role. Therefore, RNAbinding properties of several potyvirus-encoded proteins have been studied and reported for the following proteins : P1 of tobacco vein mottling potyvirus (TVMV) (Brantley & Hunt, 1993) and turnip mosaic potyvirus (TuMV) (Soumounou & Laliberte, 1994), HC-Pro of potato Y potyvirus (PVY) (Maia & Bernardi, 1996), CI of plum pox potyvirus (PPV) (Ferna! ndez et al, 1995) and tamarillo mosaic potyvirus (TaMV) (Eagles et al, 1994), and NIaPro of tobacco etch potyvirus (TEV) (Daro' s & Carrington, 1997).…”

Localization of the P1 protein of potato Y potyvirus in association with cytoplasmic inclusion bodies and in the cytoplasm of infected cells.

“…Fax j358 9 7085582. e-mail Jelena.Arbatova!Helsinki.Fi activity, the P1 protein has been shown to exhibit nonspecific RNA-binding activity (Brantley & Hunt, 1993 ;Soumounou & Laliberte, 1994). The RNA-binding properties of P1 are similar to those described for known movement proteins of plant viruses (Citovsky et al, 1991(Citovsky et al, , 1992Osman et al, 1992Osman et al, , 1993Schoumacher et al, 1992) and it has been suggested that P1 could also be involved in cell-to-cell transport of virus in plants (Atabekov & Taliansky, 1990 ;Brantley & Hunt, 1993 ;Dougherty & Semler, 1993 ;Riechmann et al, 1992).…”

Tobacco etch virus Protein P1 Traffics to the Nucleolus and Associates with the Host 60S Ribosomal Subunits during Infection

“…The P1 cistron is the most variable in size and sequence in the various species of the genus (18). The P1 protein contains a carboxy-terminal serine protease domain that catalyzes its own cleavage from the viral polyprotein (19) and exhibits a strong RNA binding activity (20,21). Although P1 contributes to the virus infectious cycle, it is not essential because a virus deletion mutant completely lacking the P1 cistron, although debilitated, is still viable (22,23).…”