Guanylyltransferase signature motifs present in metazoan, plant, and
viral capping enzymes are conserved in P. falciparum
Pgt1. The amino acid sequences are aligned for the capping enzymes of
S. cerevisiae (Sce), S. pombe (Spo),
C. albicans (Cal), Chlorella virus PBCV-1
(ChV), Caenorhabditis elegans (Cel),
mouse (Mus), Drosophila melanogaster (Dme),
Xenopus laevis (Xle), Arabidopsis
thaliana (Ath), Trypanosoma brucei gambiense
(Tbr), Crithidia fasciculata (Cfa), African swine fever
virus (ASF), and AcNPV baculovirus (AcNPV). The motifs of the P.
falciparum (Pfa) guanylyltransferase are highlighted below the
other aligned sequences. The numbers of amino acid residues separating
the motifs are indicated. The amino acids of the Sce
guanylyltransferase that are essential for function in
vivo are denoted by dots. Specific contacts between amino acid
side chains and the GTP substrate in the ChV capping enzyme–GTP
cocrystal are indicated by arrowheads.