Mutagenesis of the sindbis virus nsP1 protein: Effects on methyltransferase activity and viral infectivity

被引:68
作者
Wang, HL
ORear, J
Stollar, V
机构
[1] UNIV MED & DENT NEW JERSEY, ROBERT WOOD JOHNSON MED SCH, DEPT MOLEC GENET & MICROBIOL, PISCATAWAY, NJ 08854 USA
[2] UNIV MED & DENT NEW JERSEY, ROBERT WOOD JOHNSON MED SCH, DEPT PATHOL, PISCATAWAY, NJ 08854 USA
关键词
D O I
10.1006/viro.1996.0147
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
It has been suggested that four amino acids which are absolutely conserved in the nsP1 nonstructural proteins encoded by togaviruses and in the homologous proteins encoded by plant viruses in the Sindbis virus (SV) superfamiiy may constitute a ''methyltransferase motif.'' In the Sindbis virus nsP1 protein (540 amino acids) these four amino acids are represented by His(39), Arg(91), Asp(94), and Tyr(249). Earlier, in assays of methyltransferase (MTase) activity generated in SV-iniected cells, we had shown that amino acid changes at positions B7 and 88 of SV nsP1 resulted in a 10-fold lower K-m for S-adenosyl methionine, the methyl donor in MTase reactions. Using site-directed mutagenesis we now report the expression of nsP1 in Escherichia coli, and in the infectious clone of Sindbis virus, Toto/1101, in which His(39), Arg(91), Asp(94), and Tyr(249) were changed one at a time to Ala. We also expressed nsP1 with C-terminal deletions of varying size, as well as with internal deletions in the C-terminal portion of the protein, in E. coli. Changing His(39), Arg(91), Asp(94), or Tyr(249) to Ala led to a loss of both MTase activity and viral infectivity; however, changing Ile(389) to Vat, a conservative change in the carboxy-terminal half of nsP1, had no effect on either MTase activity or viral infectivity. With respect to the deleted forms of nsP1, a carboxy-terminal deletion of 48 amino acids was still compatible with MTase activity in vitro. However, larger deletions including those in which the amino acids between positions 442 and 492 were deleted abolished MTase activity. (C) 1995 Academic Press, Inc.
引用
收藏
页码:527 / 531
页数:5
相关论文
共 18 条
[1]   REACTION IN ALPHAVIRUS MESSENGER-RNA CAPPING - FORMATION OF A COVALENT COMPLEX OF NONSTRUCTURAL PROTEIN NSP1 WITH 7-METHYL-GMP [J].
AHOLA, T ;
KAARIAINEN, L .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1995, 92 (02) :507-511
[2]   EXTREME 5'-TERMINAL SEQUENCES OF SINDBIS VIRUS-26 AND 42-S RNA [J].
DUBIN, DT ;
TIMKO, K ;
GILLIES, S ;
STOLLAR, V .
VIROLOGY, 1979, 98 (01) :131-141
[3]   A MUTANT OF SINDBIS VIRUS WITH A HOST-DEPENDENT DEFECT IN MATURATION ASSOCIATED WITH HYPERGLYCOSYLATION OF E2 [J].
DURBIN, RK ;
STOLLAR, V .
VIROLOGY, 1984, 135 (02) :331-344
[4]   SINDBIS VIRUS MUTANTS ABLE TO REPLICATE IN METHIONINE-DEPRIVED AEDES-ALBOPICTUS CELLS [J].
DURBIN, RK ;
STOLLAR, V .
VIROLOGY, 1985, 144 (02) :529-533
[5]   ADENYLATE-RICH SEGMENT IN VIRION RNA OF SINDBIS VIRUS [J].
JOHNSTON, RE ;
BOSE, HR .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1972, 46 (02) :712-&
[7]   EXPRESSION OF SEMLIKI FOREST VIRUS NSP1-SPECIFIC METHYLTRANSFERASE IN INSECT CELLS AND IN ESCHERICHIA-COLI [J].
LAAKKONEN, P ;
HYVONEN, M ;
PERANEN, J ;
KAARIAINEN, L .
JOURNAL OF VIROLOGY, 1994, 68 (11) :7418-7425
[8]   A GENERAL-METHOD FOR RAPID SITE-DIRECTED MUTAGENESIS USING THE POLYMERASE CHAIN-REACTION [J].
LANDT, O ;
GRUNERT, HP ;
HAHN, U .
GENE, 1990, 96 (01) :125-128
[9]   EXPRESSION OF SINDBIS VIRUS NSP1 AND METHYLTRANSFERASE ACTIVITY IN ESCHERICHIA-COLI [J].
MI, S ;
STOLLAR, V .
VIROLOGY, 1991, 184 (01) :423-427
[10]   ASSOCIATION OF THE SINDBIS VIRUS-RNA METHYLTRANSFERASE ACTIVITY WITH THE NONSTRUCTURAL PROTEIN-NSP1 [J].
MI, S ;
DURBIN, R ;
HUANG, HV ;
RICE, CM ;
STOLLAR, V .
VIROLOGY, 1989, 170 (02) :385-391