tailieunhanh - Báo cáo khoa học: Autonomous folding of interdomain regions of a modular polyketide synthase

Domains within the multienzyme polyketide synthases are linked by non-catalytic sequences of variable length and unknown function. Recently, the crystal structure was reported of a portion of the linker between the acyl-transferase (AT) and ketoreductase (KR) domains from module 1 of the erythromycin synthase (6-deoxyerythronolide B synthase), as a pseudo-dimer with the adjacent ketoreductase (KR). | ễFEBS Journal Autonomous folding of interdomain regions of a modular polyketide synthase Carsten D. Richter David A. Stanmore Ricardo N. Miguel Martin C. Moncrieffe Lucky Tran Suzanne Brewerton Filip MeersmanỳỊ R. William Broadhurst and Kira J. Weissman Department of Biochemistry University of Cambridge UK Keywords genetic engineering interdomain linker modular polyketide synthase multienzyme polyketide biosynthesis Correspondence K. J. Weissman Department of PharmaceuticalBiotechnology Saarland University PO Box 151150 66041 Saarbrucken Germany Fax 49 681 302 5473 Tel 49 681 302 5497 E-mail Present address Astex Unit 436 Science Park Milton Road Cambridge UK fDepartment of Chemistry University of Cambridge UK ỊKatholieke Universiteit Leuven Department of Chemistry Belgium Department of PharmaceuticalBiotechnology Saarland University Germany Received 30 June 2006 revised 20 February 2007 accepted 27 February 2007 doi Domains within the multienzyme polyketide synthases are linked by non-catalytic sequences of variable length and unknown function. Recently the crystal structure was reported of a portion of the linker between the acyltransferase AT and ketoreductase KR domains from module 1 of the erythromycin synthase 6-deoxyerythronolide B synthase as a pseudodimer with the adjacent ketoreductase KR . On the basis of this structure the homologous linker region between the dehydratase DH and enoyl reductase ER domains in fully reducing modules has been proposed to occupy a position on the periphery of the polyketide synthases complex as in porcine fatty acid synthase. We report here the expression and characterization of the same region of the 6-deoxyerythronolide B synthase module 1 AT-KR linker without the adjacent KR domain termed AN AT1-KR1 as well as the corresponding section of the DH-ER linker. The linkers fold autonomously and are well structured. However analytical gel filtration and .