1. Structure of an mRNA Capping Enzyme Bound to the Phosphorylated Carboxy-Terminal Domain of RNA Polymerase II 
Carme Fabrega, Vincent Shen, Stewart Shuman, Christopher D. Lima 
Molecular Cell 
Volume 11, Issue 6, Pages (June 2003)
DOI: /S (03)

2. Figure 1 Structures of the Guanylyltransferase/CTD-PO4 Complexes
(A) Ribbon diagram of Cgt1 monomer A as an enzyme-guanylate (K67-GMP) in complex with phosphate (P) and 9 residues of phosphorylated CTD.
(B) Monomer B shown in complex with GTP and 17 residues of phosphorylated CTD. Cgt1 monomers A and B are colored blue to red from N- to C termini. The CTD is shown by solid bond representation and carbons colored yellow. The N- and C termini of Cgt1 and CTD peptides are indicated. Images generated with SETOR unless noted otherwise (Evans, 1993).
Molecular Cell  , DOI: ( /S (03) )

3. Figure 2 Cgt1 Surfaces Involved in CTD Interaction
(A and B) Orthogonal surface views of monomer B with solid bond representation of the CTD depicting surface and electrostatic interactions between the two molecules.
(C) Stereo view of the interactions depicted in (A). Oxygen atoms of acidic side chains on the Cgt1 surface are colored red, nitrogen atoms from histidine are light blue, and nitrogen atoms from basic residues are blue. Images rendered with PYMOL (DeLano, 2002).
Molecular Cell  , DOI: ( /S (03) )

4. Figure 3 CTD Docking Sites
(A) CDS1 is shown on the left, CDS2 on the right, and CDS3 in the middle. “N” and “C” denote CTD N- and C termini. CTD carbons colored yellow with the Cgt1 backbone colored blue below the CTD residues (from monomer B), and gray above the CTD residues (from monomer A). Hydrogen bonding interactions are depicted by dashed lines and waters shown as red spheres.
(B) Serial dilutions of S. cerevisiae ceg1Δ cultures bearing indicated CGT1 alleles containing single point mutations were spotted on YPD agar and tested for growth at 23°C (top panel), 30°C (middle panel), and 37°C (bottom panel).
(C) Serial dilutions of S. cerevisiae ceg1Δ cultures bearing indicated CGT1 alleles containing single, double, and triple point mutations were spotted on YPD agar and tested for growth at 23°C (top panel), 30°C (middle panel), and 37°C (bottom panel).
Molecular Cell  , DOI: ( /S (03) )

5. Figure 4
Distinct CTD Secondary Structures in Cgt1 versus Pin1 Complexes
(A) Yellow ribbon representation and solid bond representation for the CTD backbone and amino acids T4a-P3b, respectively, bound to CDS1 of Cgt1.
(B) As in (A) but for CTD amino acids S7b-P6c bound to CDS2 of Cgt1.
(C) Blue ribbon representation of the backbone and solid bond representation for CTD amino acids Y1-S7 bound to the WW domain of Pin1 (PDB code 1f8a). (A), (B), and (C) are shown in stereo and arranged so that protein surfaces would be located below the CTD peptide in each panel.
Molecular Cell  , DOI: ( /S (03) )

6. Figure 5 OB Fold and Triphosphatase Interaction
(A) Ribbon diagram of the OB fold (gold) highlighting solvent-exposed hydrophobic residues (red) involved in putative interactions with CaCet1. The N-terminal peptide involved in cross-domain interactions with the OB domain is also shown.
(B) Structure-based alignment for OB domain amino acid sequences for guanylyltransferases of C. albicans (Cgt1), S. cerevisiae (Ceg1), S. pombe (Pce1), mouse (Mce1), and Chlorella virus (Pbcv1). Cgt1 and Pbcv1 secondary structure elements are shown above (yellow) and below (green) the sequence alignment, respectively. Sequence identity highlight in blue, gaps indicated by dashes (-). Red arrows indicate the red amino acids in (A).
(C) Mutational effects on Cgt1-CaCet1 interaction. The y axis indicates the log of the ratio between the estimated Kd obtained for CaCet1-Cgt1 mutant pairs and wild-type Cgt1 (see Experimental Procedures).
(D) Serial dilutions of S. cerevisiae ceg1Δ strains bearing the indicated CGT1 alleles were spotted on YPD agar and grown at 23°C, 30°C, and 37°C. Bottom panel shows dosage suppression of cgt1-ts phenotypes by a plasmid encoding CaCET1( ). Mutations Y275A-L276A-Y278A, W309H, and L312A were lethal in the plasmid shuffle assay for ceg1Δ complementation.
Molecular Cell  , DOI: ( /S (03) )

7. Figure 6
Comparison of the Tertiary Structures and Active Sites of Candida and Chlorella Virus Guanylyltransferases
(A) Superposition of the N-terminal nucleotidyl transferase domains of Candida (cyan) and Chlorella virus (yellow) enzyme-GMP complexes highlights the movement of the OB domain, presumably to allow ingress of the RNA 5′ end. Lysyl-GMP adducts are shown in solid bond representation.
(B and C) Superpositions of the lysyl-GMP adducts of Candida (K67-GMP, colored in CPK with the main chain colored cyan) and Chlorella virus (colored yellow) capping enzymes.
Molecular Cell  , DOI: ( /S (03) )