Plasmodium falciparum ubiquitin-conjugating enzyme

We have solved the structures of putative ubiquitin conjugating enzyme (E2) from Plasmodium vivax
(Pv083175)
and from Plasmodium falciparum
(MAL13P1.227).
The two orthologues share 80% sequence identity with each other and over 40% identical human UBC
FLJ11011.

Similar to FLJ11011, these Plasmodium UBC structures are distinct from other members of the 30+ known human UBCs,
although their crystal structures demonstrate a typical UBC fold, with 4 anti-parallel beta strands at the center flanked by N- and C-terminal alpha-helices.
The catalytic cysteine (Cys91) is located in a groove on a large loop between â4 and á5.
In our structure, this cysteine forms a disulfide bond (2.15 Šfrom Sã to Sã) with the same cysteine from one of the symmetry related molecules,
which suggests that these Plasmodium UBC proteins are catalytically competent.

Unlike FLJ11011, Pv-UBC does not feature a dimeric conformation with swapped domains.
In gel-filtration, only monomeric protein can be seen from all the constructs purified,
with or without C-terminal domain.

See also

• other apicomplexan UBC structures from SGC;
• human UBC structures from SGC;
• other apicomplexan structures from SGC.