title: The T-region of Ti plasmids codes for an enzyme synthesizing indole-3-acetic acid.
abstract: Gene 2 from the T region of Ti plasmids appears to be expressed both in eucaryotic and in procaryotic systems. In transformed plant cells it participates in auxin-controlled growth and differentiation, and in bacteria it is expressed into a defined protein of Mr 49000. We investigated the possibility that it codes for an enzyme involved in auxin biosynthesis. Only extracts from Escherichia coli cells expressing gene 2 hydrolyzed indole-3-acetamide into a substance which was unambiguously identified as indole-3-acetic acid. The same reaction was found in Agrobacteria containing gene 2, but not in strains lacking the gene. Extracts from tobacco crown gall cells, but not from non-transformed cells, showed the same enzyme activity, and the reaction product was also identified as indole-3-acetic acid. The results indicate that gene 2 of the T region, which participates in tumorous growth of plant cells, codes both in bacteria and in plants for an amidohydrolase involved in the biosynthesis of the plant hormone indole-3-acetic acid.
mesh_terms: D000581:Amidohydrolases / Q000235:genetics*; D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005786:Gene Expression Regulation; D007210:Indoleacetic Acids / Q000096:biosynthesis* / Q000235:genetics; D010941:Plant Tumors / Q000382:microbiology; D010957:Plasmids; D012231:Rhizobium / Q000201:enzymology / Q000235:genetics*
chemical_list: D007210:Indoleacetic Acids; C030737:indoleacetic acid; D000581:Amidohydrolases; C029145:indoleacetamide hydrolase