PF3D7_1348800

PF3D7_1348800 (referred to here as Pf-E2) functions as the E2 SUMO-conjugating enzyme of the Plasmodium falciparum SUMOylation pathway, where its interaction with SUMO proteins is governed by species-specific determinants at its N-terminus (PMID:35331687). The cross-species interaction is unidirectional: Pf-SUMO engages human E2, but human SUMO1 fails to interact with Pf-E2, and critical N-terminal residues of Pf-E2 are responsible for this diminished interaction — mutating them to the corresponding human Ubc9 residues restores electrostatic, π-π, and hydrophobic contacts and enables efficient cross-species binding (PMID:35331687). Beyond this determinant of SUMO recognition (PMID:35331687), no further mechanistic detail on Pf-E2 has been characterized in the available corpus.

1. 2022 Medium

   It was unknown why the parasite and human SUMOylation machineries fail to cross-react; this work showed that N-terminal residues of Pf-E2 dictate species-specific SUMO recognition, establishing a molecular basis for a divergent parasite SUMO-conjugating enzyme.

   Evidence Biochemical and biophysical binding assays with N-terminal mutagenesis in P. falciparum Pf-E2

   PMID:35331687

   Open questions at the time

   • Single lab, single study with abstract-level detail only
   • Catalytic SUMO-conjugating activity of Pf-E2 on substrates not directly demonstrated
   • No structural model or in vivo functional consequence established

• Whether Pf-E2 catalyzes SUMO transfer to specific parasite substrates, its interacting partners in the full SUMOylation cascade, and its role in parasite biology remain uncharacterized in the available corpus.
• No SUMO substrate identified for Pf-E2
• E3 ligase or upstream E1 partners not defined in this corpus
• Cellular localization and essentiality not established