SI Legends
Supplementary Figure 1
Original gels from Figure 1
Various E2 proteins were induced with the appropriate concentration of CdSO4 for 4 h and the
associated protein complexes were purified by immunopurification with anti-FLAG M2 and
anti-HA antibodies as described in Materials and Methods. The bound proteins were eluted
with 2% sarcosyl from anti-HA agarose following IP with anti-FLAG M2 agarose. (A) The
purified E2 complexes were analyzed on a NuPAGE gel and stained with SilverXpress silver
staining kit (Invitrogen). (B) The purified E2 complexes were concentrated with acetone
precipitation, dissolved in 1X LDS sample loading buffer, and analyzed on a NuPAGE gel
followed by staining with Colloidal Blue.. A band for each E2 protein is marked with an
arrowhead and strong binding partners marked with open boxes.
Supplementary Figure 2
Papillomavirus E2 protein complexes separated by
electrophoresis for mass spectrometric analysis.
E2 protein complexes were purified by tandem affinity purification using anti-FLAG and antiHA antibodies. Purified E2 protein complexes were separated on 4-12% NuPAGE gels and
stained with Colloidal Blue. Bands (marked with arrow heads) and regions (marked with
vertical lines) were selected for mass spectrometry and are numbered to match with identified
components in Supplementary Table 1. Bands identified as mainly immunoglobulin, are
marked *. Molecular weight markers (MW) were electrophoresed in parallel and are indicated
to the left of each bgel image (in kDa).
(A) FLAG-HA tagged BPV1 E2 (a, b, two different experiments) and Mock (from cells expressing
non-tagged BPV1 E2)
(B) FLAG-HA tagged HPV8 E2 (a, b, two different experiments)
(C) FLAG-HA tagged HPV8 E2delHC (a, b, two different experiments)
(D) FLAG-HA tagged E2 protein for 11 different papillomaviruses.
Supplementary Table 1
List of all cellular proteins detected in complex with E2 proteins
Tab 1 gives an overview of all cellular proteins identified in complex with the E2 proteins
shown.
The other tabs list all cellular proteins detected in complex with individual E2 proteins with
their overall Mascot score. The top three identified peptides are shown, with their individual
Mascot scores and expect values listed. For each protein, the corresponding band or region
excised from the gels shown in Supplementary Figure 2 is listed.