HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Crawford, I. P. Articles by Yanofsky, C. Search for Related Content PubMed PubMed Citation Articles by Crawford, I. P. Articles by Yanofsky, C. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 262, Issue 1, 239-244, Jan, 1987

Crucial role of the connecting region joining the two functional domains of yeast tryptophan synthetase

IP Crawford, M Clarke, M van Cleemput and C Yanofsky

We constructed a hybrid plasmid expressing yeast tryptophan synthetase in Escherichia coli. Several deletion variants lacking the A or B domains of this polypeptide (recognized by their homology to the alpha and beta subunits of prokaryotic tryptophan synthetase) showed no enzymatic activity and failed to substitute for the corresponding E. coli subunits. To examine the role of a presumed interdomain connecting region in the yeast enzyme, we constructed a variant lacking 18 amino acids in that region. The variant polypeptide was completely inactive. Replacing 14 of the 18 missing amino acids with a segment having a different sequence partially restored activity. A spontaneous revertant was characterized and shown to have a duplication of 16 amino acid residues in this region; the activity of the duplication polypeptide was better than that of the 14-residue replacement. If confirmed by additional studies, our finding that the length of the connecting region is more critical than its sequence has implications for understanding the origin of gene fusions during evolution as well as for designing artificial fusions.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				G. Xie, N. O. Keyhani, C. A. Bonner, and R. A. Jensen Ancient Origin of the Tryptophan Operon and the Dynamics of Evolutionary Change Microbiol. Mol. Biol. Rev., September 1, 2003; 67(3): 303 - 342. [Abstract] [Full Text] [PDF]

				H. S. Seo, Y. J. Koo, J. Y. Lim, J. T. Song, C. H. Kim, J. K. Kim, J. S. Lee, and Y. D. Choi Characterization of a Bifunctional Enzyme Fusion of Trehalose-6-Phosphate Synthetase and Trehalose-6-Phosphate Phosphatase of Escherichia coli Appl. Envir. Microbiol., June 1, 2000; 66(6): 2484 - 2490. [Abstract] [Full Text]

				K. Kurima, B. Singh, and N. B. Schwartz Genomic Organization of the Mouse and Human Genes Encoding the ATP Sulfurylase/Adenosine 5'-Phosphosulfate Kinase Isoform SK2 J. Biol. Chem., November 19, 1999; 274(47): 33306 - 33312. [Abstract] [Full Text] [PDF]

				M. C. Yee, V. Horn, and C. Yanofsky On the Role of Helix 0of the Tryptophan Synthetase alpha Chain of Escherichia coli J. Biol. Chem., June 21, 1996; 271(25): 14754 - 14763. [Abstract] [Full Text] [PDF]