FIG 3.

Relative abundance of transport proteins in the metaproteome. Black, Hht. litchfieldiae; dark gray, DL31; light gray, Hrr. lacusprofundi. Abundance was calculated relative to the sum of the normalized total spectrum count for transport proteins across all 15 samples. In addition to the relatively abundant ABC and TRAP/TTT transporter proteins shown, other transporter proteins were identified, representing 18, 17, and 3% of the transport spectra for Hht. litchfieldiae, DL31, and Hrr. lacusprofundi, respectively (see Table S4 in the supplemental material).