In order to study the tryptophan biosynthetic enzymes of the plant Arabidopsis thaliana, polyclonal antibodies were raised against five of the tryptophan biosynthetic pathway proteins: anthranilate synthase subunit, phosphoribosylanthranilate transferase, phosphoribosylanthranilate isomerase, and the tryptophan synthase and subunits. Immunoblot analysis of Arabidopsis leaf protein extracts revealed that the antibodies identify the corresponding proteins that are enriched in Arabidopsis chloroplast fractions. Precursors of phosphoribosylanthranilate isomerase and tryptophan synthase subunit were synthesized by in vitro translation. The precursors were efficiently imported and processed by isolated spinach chloroplasts, and the cleavage sites within the precursors were determined. These results provide the first direct evidence that the tryptophan biosynthetic enzymes from Arabidopsis are synthesized as higher molecular weight precursors and then imported into chloroplasts and processed into their mature forms.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				J. A. Quiel and J. Bender Glucose Conjugation of Anthranilate by the Arabidopsis UGT74F2 Glucosyltransferase Is Required for Tryptophan Mutant Blue Fluorescence J. Biol. Chem., February 14, 2003; 278(8): 6275 - 6281. [Abstract] [Full Text] [PDF]

				D. J. Kliebenstein, J. E. Lim, L. G. Landry, and R. L. Last Arabidopsis UVR8 Regulates Ultraviolet-B Signal Transduction and Tolerance and Contains Sequence Similarity to Human Regulator of Chromatin Condensation 1 Plant Physiology, September 1, 2002; 130(1): 234 - 243. [Abstract] [Full Text] [PDF]

				Y. Tozawa, H. Hasegawa, T. Terakawa, and K. Wakasa Characterization of Rice Anthranilate Synthase {alpha}-Subunit Genes OASA1 and OASA2. Tryptophan Accumulation in Transgenic Rice Expressing a Feedback-Insensitive Mutant of OASA1 Plant Physiology, August 1, 2001; 126(4): 1493 - 1506. [Abstract] [Full Text] [PDF]

				H.-J. Cho, J. E. Brotherton, H.-S. Song, and J. M. Widholm Increasing Tryptophan Synthesis in a Forage Legume Astragalus sinicus by Expressing the Tobacco Feedback-Insensitive Anthranilate Synthase (ASA2) Gene Plant Physiology, July 1, 2000; 123(3): 1069 - 1076. [Abstract] [Full Text]

				H. Lu and T. D. McKnight Tissue-Specific Expression of the beta -Subunit of Tryptophan Synthase in Camptotheca acuminata, an Indole Alkaloid-Producing Plant Plant Physiology, May 1, 1999; 120(1): 43 - 52. [Abstract] [Full Text]

				B. N. Krath and B. Hove-Jensen Organellar and Cytosolic Localization of Four Phosphoribosyl Diphosphate Synthase Isozymes in Spinach Plant Physiology, February 1, 1999; 119(2): 497 - 506. [Abstract] [Full Text]

				M.-H. Hsieh, H.-M. Lam, F. J. van de Loo, and G. Coruzzi A PII-like protein in Arabidopsis: Putative role in nitrogen sensing PNAS, November 10, 1998; 95(23): 13965 - 13970. [Abstract] [Full Text] [PDF]

				D. J. Kliebenstein, R.-A. Monde, and R. L. Last Superoxide Dismutase in Arabidopsis: An Eclectic Enzyme Family with Disparate Regulation and Protein Localization Plant Physiology, October 1, 1998; 118(2): 637 - 650. [Abstract] [Full Text]

				A. L. Palombella and S. K. Dutcher Identification of the Gene Encoding the Tryptophan Synthase beta -Subunit from Chlamydomonas reinhardtii Plant Physiology, June 1, 1998; 117(2): 455 - 464. [Abstract] [Full Text]

				J. Zhao, C. C. Williams, and R. L. Last Induction of Arabidopsis Tr yptophan Pathway Enzymes and Camalexin by Amino Acid Star vation, Oxidative Stress, and an Abiotic Elicitor PLANT CELL, March 1, 1998; 10(3): 359 - 370. [Abstract] [Full Text] [PDF]

				R. H. Köhler, J. Cao, W. R. Zipfel, W. W. Webb, and M. R. Hanson Exchange of Protein Molecules Through Connections Between Higher Plant Plastids Science, June 27, 1997; 276(5321): 2039 - 2042. [Abstract] [Full Text]

				A. K. Hull, R. Vij, and J. L. Celenza Arabidopsis cytochrome P450s that catalyze the first step of tryptophan-dependent indole-3-acetic acid biosynthesis PNAS, February 29, 2000; 97(5): 2379 - 2384. [Abstract] [Full Text] [PDF]