Biological activity of the rolB-like 5' end of the A4-orf8 gene from the Agrobacterium rhizogenes TL-DNA.
The iaaM gene from different plant-associated bacteria encodes a tryptophan monooxygenase (IaaM) that catalyzes the synthesis of indole-3-acetamide (IAM), a precursor of indole-3-acetic acid (IAA). Unlike the IaaM proteins from other bacteria, Agrobacterium spp. T-DNA-encoded IaaM proteins carry a 200 amino acid N-terminal extension with low homology to various members of the RolB protein family. This family is composed of 18 highly divergent T-DNA-encoded proteins, the basic functions of which are still largely undetermined. Deletion of the 5' rolB-like extension of the iaaM gene from Agrobacterium tumefaciens strain Ach5 did not lead to a reduction in IAM synthesis in plants. When expressed in tobacco, the rolB-like fragment did not affect growth or morphology. An iaaM homolog (A4-orf8) from the TL-DNA of Agrobacterium rhizogenes strain A4 also was investigated. Neither the full-size A4-orf8 gene nor the 5'-truncated form induced detectable IAM synthesis. Plants expressing the rolB-like part of the A4-orf8 gene, however, were dwarfed and mottled to various extents and synthesized abnormally high amounts of glucose, fructose, sucrose, and starch.
Otten
L
L
Department of Cell Biology, Plant Molecular Biology Institute of the CNRS, Strasbourg, France. leon.otten@ibmp-ulp.u-strasbg.fr
Helfer
A
A
D016960:Agrobacterium tumefaciens / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D050260:Carbohydrate Metabolism; D004269:DNA, Bacterial / Q000032:analysis; D005798:Genes, Bacterial; D007210:Indoleacetic Acids / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D015513:Oncogene Proteins / Q000235:genetics*; D016366:Open Reading Frames; D018517:Plant Roots / Q000378:metabolism; D010947:Plants, Toxic; D012231:Rhizobium / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D014026:Nicotiana / Q000378:metabolism; D014365:Tryptophan Hydroxylase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001617:beta-Glucosidase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007210:Indoleacetic Acids; D015513:Oncogene Proteins; C036483:T-DNA; C081170:iaaM protein, Agrobacterium; C015950:indoleacetamide; D014365:Tryptophan Hydroxylase; C092241:RolB protein, Agrobacterium rhizogenes; D001617:beta-Glucosidase