1. Volume 114, Issue 5, Pages 1030-1035 (March 2018)
Structural Conservation and Effects of Alterations in T Cell Receptor Transmembrane Interfaces 
Soohyung Park, Logesvaran Krshnan, Melissa J. Call, Matthew E. Call, Wonpil Im 
Biophysical Journal 
Volume 114, Issue 5, Pages (March 2018)
DOI: /j.bpj
Copyright © 2018 Biophysical Society Terms and Conditions

2. Figure 1
(A and B) Organization of the αβ TCR complex in the membrane. (A) Three conserved basic residues (Arg and Lys; cyan circles) in TCRα and TCRβ TM domains guide assembly with CD3δε, CD3γε, and ζζ signaling dimers containing complementary acidic TM residues (Asp and Glu; red circles) (6). (B) View down the TM axis showing how signaling dimers are arranged around a specific αβ TM structure (12). For clarity, only conserved basic residues (αR27, K32, and βK25) and polar αβ interface residues (αN37, T41, and βY29) are shown. Predicted H-bonds are indicated as dashed lines. To see this figure in color, go online.
Biophysical Journal  , DOI: ( /j.bpj )
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3. Figure 2
TCR heterodimers adopt compatible interfaces among αβ, δγ, and pre-Tαβ TM assemblies. (A) Sequences of TCR TMs used in the study. Charged residues (Arg and Lys, shown in bold italic) for the interface to signaling molecules are mutated to Leu in simulations and the conserved residues in the C-terminal side (Asn/Asp, Thr, and Tyr) are shown in bold. (B) Representative TCR TM structure models from MD simulations, and interhelical H-bonds are shown as red dotted lines. The structure of pre-Tαβ is that with protonated Asp in pre-Tα. The positions of Arg and Lys residues (mutated to Leu) are marked by cyan spheres. (C) RMSD between TCR TM models and the previously reported αβ TM model (12) over the 200-ns simulation time, where five independent simulations for each TM model are shown in different colors. (D) Distribution of distances between conserved polar residues. For αβ TM, distances between Cβ atom of residues α37/α41 and Cζ atom of β29 (dα37–β29/dα41–β29) were measured. For TCRδγ, the distances were measured between δ37/δ41 and γ29 residues. Similarly, the distances between pre-Tα37/pre-Tα41 and β29 were measured for pre-Tαβ. To guide visual inspection, the corresponding distances for the previously reported αβ TM model are shown in blue lines. The density of the distribution is shown in a rainbow color scheme. In (C) and (D), ionization states of Asp in pre-Tα are indicated in the corresponding panels. To see this figure in color, go online.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2018 Biophysical Society Terms and Conditions

4. Figure 3
Effects of mutations on TCRαβ TM structure and stability. In the first four mutations (αN37A, αN37L, αN37F, and βV33F), alterations were made to the residues buried in the intimately packed regions. In the latter four mutations (αT41A, βY29F, αT41A-βY29F, and triple mutant), interhelical H-bonds were disrupted, and all three polar residues were eliminated in the triple mutation αN37A-αT41A-βY29F. (A) C-terminal interfaces of mutant TCRαβ TM models in which mutated residues are shown in orange and interhelical H-bonds are shown as red dotted lines. The Arg and Lys residues (mutated to Leu) interfacing to signaling modules are marked by cyan spheres. (B) RMSD between mutant TCRαβ TM models and the previously reported TCRαβ TM model (12) over the 200-ns simulation time, where three independent simulations for each TM model are shown in different colors. (C) Distribution of distances between residues α37 and β29 (dα37–β29), and α41 and β29 (dα41–β29), where the distances are measured between the Cβ atom of α37/α41 and the Cζ atom of β29. To guide visual inspection, the corresponding distances for the previously reported αβ TM model are shown in blue lines. To see this figure in color, go online.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2018 Biophysical Society Terms and Conditions

5. Figure 4
The precise interhelical interfaces and their stability are key determinants of structural integrity in the assembled TCR-CD3 complex. (A) Recovery of intact TCR-CD3 complexes with indicated TM mutations relative to the wild-type human TCRαβ TM sequences, reprinted from (12). The statistical significance (ns: not significant; ∗P < 0.05; ∗∗∗P < 0.001; and ∗∗∗∗P < ) was determined using an ordinary one-way ANOVA uncorrected Fisher’s least significant difference test with single pooled variance. (B) Correlation of interhelical contact maps between mutant αβ TM models and the previously reported wild-type αβ TM model. Statistical significance could not be evaluated in this analysis due to the large variations inherent in the measurements from destabilized mutants. To see this figure in color, go online.
Biophysical Journal  , DOI: ( /j.bpj )
Copyright © 2018 Biophysical Society Terms and Conditions