Contribution of Transcriptomics to Systems-Level Understanding of Methanogenic Archaea
Figure 2
Observed regulatory patterns in hydrogenotrophic methanogenesis. Regulation steps for hydrogenotrophic methanogenesis are summarized from published sources discussed in this paper. Conditions, (syntrophic interaction or H2 limitation) causing upregulation and downregulation of enzyme transcript levels are indicated in red and blue, respectively. Abbreviations are as per Figure 1 with the addition of the following: F420: coenzyme F420; Fd: ferredoxin; Frh: F420-reducing hydrogenase; Fdh: formate dehydrogenase; Fwd: formyl-MFR dehydrogenase; Mtd: F420-dependent methylene-H4MPT dehydrogenase; Hmd: H2-dependent methylene-H4MPT dehydrogenase; Mer: F420-dependent methylene-H4MPT reductase; Mcr: methylcoenzyme M reductase. (The dotted lined box highlights two isofunctional enzymes oppositely regulated by H2 limitation).
