Role of type II thioesterases: evidence for removal of short acyl chains produced by aberrant decarboxylation of chain extender units

被引:161
作者
Heathcole, ML
Staunton, J
Leadlay, PF
机构
[1] Univ Cambridge, Cambridge Ctr Mol Recognit, Cambridge CB2 1EW, England
[2] Univ Cambridge, Chem Lab, Cambridge CB2 1EW, England
[3] Univ Cambridge, Cambridge Ctr Mol Recognit, Cambridge CB2 1GA, England
[4] Univ Cambridge, Dept Biochem, Cambridge CB2 1GA, England
来源
CHEMISTRY & BIOLOGY | 2001年 / 8卷 / 02期
基金
英国生物技术与生命科学研究理事会; 英国工程与自然科学研究理事会; 英国惠康基金;
关键词
decarboxylation; editing enzyme; polyketide synthase; tylosin biosynthesis; type II thioesterase;
D O I
10.1016/S1074-5521(01)00002-3
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Background: Modular polyketide synthases (PKSs) function as molecular assembly lines in which polyketide chains are assembled by successive addition of chain extension units. At the end of the assembly line, there is usually a covalently linked type I thioesterase domain (TE I), which is responsible for release of the completed acyl chain from its covalent link to the synthase. Additionally, some PKS clusters contain a second thioesterase gene (TE II) for which there is no established role. Disruption of the TE II genes from several PKS clusters has shown that the TE II plays an important role in maintaining normal levels of antibiotic production. It has been suggested that the TE II fulfils this role by removing aberrant intermediates that might otherwise block the PKS complex. Results: We show that recombinant tylosin TE II behaves in vitro as a TE towards a variety of N-acetylcysteamine and p-nitrophenyl eaters. The trends of hydrolytic activity determined by the kinetic parameter k(cat)/K-M for the analogues tested indicates that simple fatty acyl chains are effective substrates. Analogues that modelled aberrant forms of putative tylosin biosynthetic intermediates were hydrolysed at low rates. Conclusions: The behaviour of tylosin TE II in vitro is consistent with its proposed role as an editing enzyme. Aberrant decarboxylation of a malonate-derived moiety attached to an acyl carrier protein (ACP) domain may generate an acetate, propionate or butyrate residue on the ACP thiol. Our results suggest that removal of such groups is a significant role of TE II. (C) 2001 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:207 / 220
页数:14
相关论文
共 44 条
[1]   THE THIOESTERASE OF THE ERYTHROMYCIN-PRODUCING POLYKETIDE SYNTHASE - MECHANISTIC STUDIES IN-VITRO TO INVESTIGATE ITS MODE OF ACTION AND SUBSTRATE-SPECIFICITY [J].
AGGARWAL, R ;
CAFFREY, P ;
LEADLAY, PF ;
SMITH, CJ ;
STAUNTON, J .
JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1995, (15) :1519-1520
[2]  
[Anonymous], 1967, METHODS ENZYMOL
[3]   THE MULTIFUNCTIONAL 6-METHYLSALICYLIC ACID SYNTHASE GENE OF PENICILLIUM-PATULUM - ITS GENE STRUCTURE RELATIVE TO THAT OF OTHER POLYKETIDE SYNTHASES [J].
BECK, J ;
RIPKA, S ;
SIEGNER, A ;
SCHILTZ, E ;
SCHWEIZER, E .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1990, 192 (02) :487-498
[4]   A chain initiation factor common to both modular and aromatic polyketide synthases [J].
Bisang, C ;
Long, PF ;
Cortés, J ;
Westcott, J ;
Crosby, J ;
Matharu, AL ;
Cox, RJ ;
Simpson, TJ ;
Staunton, J ;
Leadlay, PF .
NATURE, 1999, 401 (6752) :502-505
[5]   Engineering of a minimal modular polyketide synthase, and targeted alteration of the stereospecificity of polyketide chain extension [J].
Bohm, I ;
Holzbaur, IE ;
Hanefeld, U ;
Cortes, J ;
Staunton, J ;
Leadlay, PF .
CHEMISTRY & BIOLOGY, 1998, 5 (08) :407-412
[6]   Impact of thioesterase activity on tylosin biosynthesis in Streptomyces fradiae [J].
Butler, AR ;
Bate, N ;
Cundliffe, E .
CHEMISTRY & BIOLOGY, 1999, 6 (05) :287-292
[7]   AN ACYL-CARRIER-PROTEIN-THIOESTERASE DOMAIN FROM THE 6-DEOXYERYTHRONOLIDE-B SYNTHASE OF SACCHAROPOLYSPORA-ERYTHRAEA - HIGH-LEVEL PRODUCTION, PURIFICATION AND CHARACTERIZATION IN ESCHERICHIA-COLI [J].
CAFFREY, P ;
GREEN, B ;
PACKMAN, LC ;
RAWLINGS, BJ ;
STAUNTON, J ;
LEADLAY, PF .
EUROPEAN JOURNAL OF BIOCHEMISTRY, 1991, 195 (03) :823-830
[8]   NARGENICIN BIOSYNTHESIS - INCORPORATION OF POLYKETIDE CHAIN ELONGATION INTERMEDIATES AND SUPPORT FOR A PROPOSED INTRAMOLECULAR DIELS-ALDER CYCLIZATION [J].
CANE, DE ;
TAN, WT ;
OTT, WR .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1993, 115 (02) :527-535
[9]   REPOSITIONING OF A DOMAIN IN A MODULAR POLYKETIDE SYNTHASE TO PROMOTE SPECIFIC CHAIN CLEAVAGE [J].
CORTES, J ;
WIESMANN, KEH ;
ROBERTS, GA ;
BROWN, MJB ;
STAUNTON, J ;
LEADLAY, PF .
SCIENCE, 1995, 268 (5216) :1487-1489
[10]   Thioesterases and the premature termination of polyketide chain elongation in rifamycin B biosynthesis by Amycolatopsis mediterranei S699 [J].
Doi-Katayama, Y ;
Yoon, YJ ;
Choi, CY ;
Yu, TW ;
Floss, HG ;
Hutchinson, CR .
JOURNAL OF ANTIBIOTICS, 2000, 53 (05) :484-495