Fig. 6: Cellular and viral CLCC1 homologs share high sequence and structural similarity.
From: ER protein CLCC1 promotes nuclear envelope fusion in herpesviral and host processes
a Domain architecture of three cCLCC1 homologs [human, channel catfish Ictalurus punctatus (IctaPu), pacific oyster Crassostrea gigas (CraGi)] and two vCLCC1 homologs (IcHV1 ORF16a and OsHV-1 ORF57). Structural elements and domains were assigned based on structural predictions and secondary structure assignments and are colored as follows: signal sequence (SS, gray), transmembrane helix 1 (TM1, blue), TM2 (deep teal), fist domain (FD, magenta), amphipathic helix (AH, orange), and TM3 (teal). S-S = predicted disulfide bond (purple). Transmembrane domains were predicted by TMHMM 2.0 (https://services.healthtech.dtu.dk/services/TMHMM-2.0/). b Sequence alignment of human (Homo), mouse (MusMus), Zebrafish (DanRe), African clawed frog (XenoLa), Pacific oyster (CraGi), Blacklip abalone (HaliRu), Channel catfish (IctaPu), American eel (AngRo) CLCC1 and the viral homologs OsHV1 ORF57, AbHV1 ORF90, IcHV1 ORF16A, AngHV1 ORF112 in the conserved core region (compared to human 117-348). Alignment was generated using Clustal Omega (https://www.ebi.ac.uk/jdispatcher/msa/clustalo) and visualized using Espript 3.0 (https://espript.ibcp.fr). Similar residues are colored yellow and conserved residue are colored red. Secondary structure elements and domains were assigned based on Alphafold 3.0 and TMHMM2.0 predictions. c Ribbon diagrams of AlphaFold3 models of human CLCC1, IctaPu CLCC1, CraGi CLCC1, IcHV1 ORF16a, and OsHV-1 ORF57. Structural models were generated using the AlphaFold 3.0 online server (https://alphafoldserver.com/) and displayed using Pymol. Structural elements and domains are colored as in (A) and labeled. d An AlphaFold model of human CLCC1 cartoon representation. Structural elements and domains are colored as in (c) and labeled. Residues 365-539 were unstructured and excluded for clarity. 10 residues that are invariant across 8 representative animal and 4 herpesviral homologs in b are shown in sphere representation and colored in red, except cysteines, which are shown in purple. Figure 6c: Ribbon diagrams of AlphaFold3 models of human CLCC1, IctaPuCLCC1, CraGi CLCC1, IcHV1 ORF16a, and OsHV-1 ORF57. Created in BioRender. Dai, B. (2025) https://BioRender.com/bies72m.
