Modification of the protein expression pattern induced in the nitrogen-fixing actinomycete Frankia sp. strain ACN14a-tsr by root exudates of its symbiotic host Alnus glutinosa and cloning of the sodF gene.
Two-dimensional (2-D) polyacrylamide gel electrophoresis was used to detect proteins induced in Frankia sp. strain ACN14a-tsr by root exudates of its symbiotic host, Alnus glutinosa. The 5 most prominent proteins were purified from 2-D gels and characterized by N-terminal sequencing. All of these proteins had a high percentage of similarity with known stress proteins. One protein match was the Fe superoxide dismutase (Fe-SOD), another was a tellurite resistance protein (Ter), the third was a bacterioferritin comigratory protein (Bcp); and two matches, differing only by their isoelectric point, were the same small heat shock protein (Hsp), a major immune reactive protein found in mycobacteria. This suggests that the symbiotic microorganism Frankia, first responds with a normal stress response to toxic root products of its symbiotic host plant. To confirm its identity, the gene corresponding to the Fe-SOD protein, sodF was isolated from a genomic library by a PCR-approach and sequenced. It is the first stress response gene characterized in Frankia.
Hammad
Y
Y
Ecologie Microbienne, UMR CNRS 5557, Université Lyon 1, Villeurbanne, France.
Maréchal
J
J
Cournoyer
B
B
Normand
P
P
Domenach
A M
AM
D000192:Actinomycetales / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029661:Alnus / Q000382:microbiology*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D015180:Electrophoresis, Gel, Two-Dimensional; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D018517:Plant Roots / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013482:Superoxide Dismutase / Q000235:genetics* / Q000378:metabolism; D013559:Symbiosis
D001426:Bacterial Proteins; D013482:Superoxide Dismutase