Fig. 3: Sequence and structural analysis of PET hydrolases.

a Annotated multiple sequence alignment (MSA) of IsPETase²⁴, LCC²⁵, and PHL7²⁶. In each panel, an MSA is shown for the 3 protein sequences performed by Clustal Omega¹⁵⁷ on the EMBL-EBI Webserver. The 5 panels span the entire protein sequences, with residue numbers at the right. Above the MSAs are images showing the secondary structure, performed using ESPript 3.0¹⁵⁸, from the crystal structures for IsPETase (PDB: 5XJH⁸⁴), LCC (PDB: 4EB0²⁵), and PHL7 (PDB: 7NEI²⁶). Nomenclature for the MSA is standard: * denotes identical residues, : denotes conserved residues, and . denotes semi-conserved residues. Images for secondary structure represent: α-helices as numbered α/squiggles, 3₁₀ helices as numbered η/squiggles, β-strands as numbered β/arrows, and β-turns as TT. Residues are colored as follows: orange for native cysteine residues (which are part of native disulfide bonds), green for residues corresponding to subsite I (classified by Richter, et al.⁵⁰), cyan for residues corresponding to subsite II (classified by Richter, et al.⁵⁰), red for the catalytic triad, blue for the extended loop region, and magenta for residues that could form disulfide bonds or salt bridges with other magenta residues, as discussed in the text. b Modeled structures of IsPETase (magenta), LCC (cyan), and PHL7 (green) overlaid and docked to the PET3mer. c A surface representation of PHL7 docked to the PET3mer, focusing on the substrate binding groove, with protein regions highlighted according to the colors scheme in (a) and residues labeled.