Number of subunits for which Glu5/Phe1 hydrogen bonding1 is observed.

1Hydrogen bonds were defined with a 3 Å distance cutoff, and a 20 degree angle cutoff from linear bonding. Only hydrogen bonds involving “bulk” subunits were included in the analysis.2Intra-subunit Glu5/Phe1 hydrogen bonding occurs within a single subunit.3Inter-subunit Glu5/Phe1 hydrogen bonding occurs between the n to n+1 subunits in the GC-T4P filament.4Number of intra-subunit or inter-subunit Glu5/Phe1 hydrogen bonds that occur for less than 25% of the simulation time.5Number of intra-subunit or inter-subunit Glu5/Phe1 hydrogen bonds that occur for greater than 25% of the simulation time.