Skip to main content
. 2025 Jul 23;26(15):7121. doi: 10.3390/ijms26157121

Figure 1.

Figure 1

Structural organization of OSCA1.2 channel and location of BzF-substituted residues. (A) Ribbon diagram of the transmembrane protein complex showing one monomer highlighted in color and the remaining subunit in gray. Individual transmembrane helices (TMs) are colored distinctly to illustrate their arrangement within the membrane according to the labels in (B). Intracellular domain is shown in light green. (B) Schematic topology model of a single monomer, displaying the arrangement of transmembrane helices (TM0–TM10), N-terminal domain (NTD), and C-terminal domain (CTD). Intracellular helices (ILH1–ILH4) and intracellular loops (IL1–IL4) are shown below the membrane-spanning region. (C) OSCA1.2 channel in a dimeric assemble highlighting residues substituted with BzF for crosslinking assays (see Figure 2). Residues F22, H236, F324, R343, W361, and F389 (green subunit) are shown in van der Waals representation. (D) Schematic of the genetic code expansion strategy used for site-specific incorporation of BzF into OSCA1.2. The amber stop codon (TAG) is introduced at selected sites in the OSCA1.2 gene. Co-expression of an orthogonal tRNA/synthetase pair enables BzF incorporation during translation, allowing UV-induced crosslinking of proximal residues in the protein.