The structural basis of chain length control in Rv1086 |
| |
Authors: | Wang Wenjian Dong Changjiang McNeil Michael Kaur Devinder Mahapatra Sebabrata Crick Dean C Naismith James H |
| |
Institution: | 1 Centre for Biomolecular Science, The University, St. Andrews, Scotland KY16 9RH, UK 2 Mycobacteria Research Laboratories, Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, CO 80523, USA |
| |
Abstract: | In Mycobacterium tuberculosis, two related Z-prenyl diphosphate synthases, E,Z-farnesyl diphosphate synthase (Rv1086) and decaprenyl diphosphate synthase (Rv2361c), work in series to synthesize decaprenyl phosphate (C50) from isopentenyl diphosphate and E-geranyl diphosphate. Decaprenyl phosphate plays a central role in the biosynthesis of essential mycobacterial cell wall components, such as the mycolyl-arabinogalactan-peptidoglycan complex and lipoarabinomannan; thus, its synthesis has attracted considerable interest as a potential therapeutic target. Rv1086 is a unique prenyl diphosphate synthase in that it adds only one isoprene unit to geranyl diphosphate, generating the 15-carbon product (E,Z-farnesyl diphosphate). Rv2361c then adds a further seven isoprene units to E,Z-farnesyl diphosphate in a processive manner to generate the 50-carbon prenyl diphosphate, which is then dephosphorylated to generate a carrier for activated sugars. The molecular basis for chain-length discrimination by Rv1086 during synthesis is unknown. We also report the structure of apo Rv1086 with citronellyl diphosphate bound and with the product mimic E,E-farnesyl diphosphate bound. We report the structures of Rv2361c in the apo form, with isopentenyl diphosphate bound and with a substrate analogue, citronellyl diphosphate. The structures confirm the enzymes are very closely related. Detailed comparison reveals structural differences that account for chain-length control in Rv1086. We have tested this hypothesis and have identified a double mutant of Rv1086 that makes a range of longer lipid chains. |
| |
Keywords: | CITPP (S)-(&minus )-β-citronellyl diphosphate EZ-FPP ω E Z-farnesyl diphosphate EE-FPP ω E E-farnesyl diphosphate GPP geranyl diphosphate IPP isopentyl diphosphate Pol-P polyprenyl phosphate TLC thin-layer chromatography UDPS undecaprenyl diphosphate synthase |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|