National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
R01AI165782
米国
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)
AI108889
米国
National Science Foundation (NSF, United States)
MCB1902449
米国
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)
R01NS108151
米国
National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK)
R01DK135088
米国
引用
ジャーナル: Nat Commun / 年: 2025 タイトル: A fiducial-assisted strategy compatible with resolving small MFS transporter structures in multiple conformations using cryo-EM. 著者: Pujun Xie / Yan Li / Gaëlle Lamon / Huihui Kuang / Da-Neng Wang / Nathaniel J Traaseth / 要旨: Advancements in cryo-EM have stimulated a revolution in structural biology. Yet, for membrane proteins near the cryo-EM size threshold of approximately 40 kDa, including transporters and G-protein ...Advancements in cryo-EM have stimulated a revolution in structural biology. Yet, for membrane proteins near the cryo-EM size threshold of approximately 40 kDa, including transporters and G-protein coupled receptors, the absence of distinguishable structural features makes image alignment and structure determination a significant challenge. Furthermore, resolving more than one protein conformation within a sample, a major advantage of cryo-EM, represents an even greater degree of difficulty. Here, we describe a strategy for introducing a rigid fiducial marker (BRIL domain) at the C-terminus of membrane transporters from the Major Facilitator Superfamily (MFS) with AlphaFold2. This approach involves fusion of the last transmembrane domain helix of the target protein with the first helix of BRIL through a short poly-alanine linker to promote helicity. Combining this strategy with a BRIL-specific Fab, we elucidated four cryo-EM structures of the 42 kDa Staphylococcus aureus transporter NorA, three of which were derived from a single sample corresponding to inward-open, inward-occluded, and occluded conformations. Hence, this fusion construct facilitated experiments to characterize the conformational landscape of NorA and validated our design to position the BRIL/antibody pair in an orientation that avoids steric clash with the transporter. The latter was enabled through AlphaFold2 predictions, which minimized guesswork and reduced the need for screening several constructs. We further validated the suitability of the method to three additional MFS transporters (GlpT, Bmr, and Blt), results that supported a rigid linker between the transporter and BRIL. The successful application to four MFS proteins, the largest family of secondary transporters in nature, and analysis of predicted structures for the family indicates this strategy will be a valuable tool for studying other MFS members using cryo-EM.
名称: NorA-BRIL(3A)-Fab36-FabBRIL / タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all 詳細: FabBRIL was added but not built in model due to masking. Here is its sequence: Heavy chain: ...詳細: FabBRIL was added but not built in model due to masking. Here is its sequence: Heavy chain: SEVQLVESGGGLVQPGGSLRLSCAASGFNVVDFSLHWVRQAPGKGLEWVAYISSSSGSTSYADSVKGRFTISADTSKNTAYLQMNSLRAEDTAVYYCARWGYWPGEPWWKAFDYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKS Light chain: DIQMTQSPSSLSASVGDRVTITCRASQSVSSAVAWYQQKPGKAPKLLIYSASSLYSGVPSRFSGSRSGTDFTLTISSLQPEDFATYYCQQYLYYSLVTFGQGTKVEIKRTVAAPSVFIFPPSDSQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRG
由来(天然)
生物種: Staphylococcus aureus (黄色ブドウ球菌)
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分子 #1: NorA-BRIL(3A) fusion
分子
名称: NorA-BRIL(3A) fusion / タイプ: protein_or_peptide / ID: 1 詳細: NorA-BRIL(3A) fusion details: M1 to R380 is NorA domain; A381 to A383 is the 3A linker; A384 to L490 is Bril domain (most residues for Bril domain were not built since a mask was added only ...詳細: NorA-BRIL(3A) fusion details: M1 to R380 is NorA domain; A381 to A383 is the 3A linker; A384 to L490 is Bril domain (most residues for Bril domain were not built since a mask was added only around NorA domain during data processing) コピー数: 1 / 光学異性体: LEVO
ソフトウェア - 名称: cryoSPARC (ver. v3.3.1) ソフトウェア - 詳細: Patch CTF estimation (multi) was used for CTF correction 詳細: Patch CTF estimation (multi) was used for CTF correction タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION