Variant of the EMP pathway in T. tenax. The enzymes corresponding to homologs identified in this study are shown in grey-shaded boxes; enzymes identified and characterized previously are shown in open boxes. Open arrows indicate irreversible reactions. For abbreviations of enzyme names, see Table 1.

Variants of the ED pathway in T. tenax. The enzymes identified in the T. tenax genome are shown in grey-shaded boxes, and the previously characterized GDH is shown in an open box. The central intermediate KDG of both variants is boxed. Closed arrows indicate the reactions of the nonphosphorylative version of the ED pathway; open arrows indicate the reactions of the semiphosphorylative version. Grey-shaded arrows mark reactions involved in both versions. For abbreviations of enzyme names, see Table 2.

(A) Organization of functionally related genes of the central carbohydrate metabolism in T. tenax. (Gene names are given in alphabetical order at the end of the legend; gene data are given in Table 1 to Table 6.) (B) Putative promoter structures of genes organized in operons. The nucleotide sequences (5′ end) and upstream regions of genes are shown. The putative crenarchaeal promoter sequences (3, 59, 60) with BRE sites [crenarchaeal consensus sequence (A/G)N(A/T)AA(A/T)] and the TATA box [crenarchaeal consensus sequence (C/T)TTTTAAA] are in light and dark grey boxes, respectively. Putative Shine-Dalgarno sequences (GAGG) (29) are underlined, the putative start codon is shown in boldface characters, and the stop codon of preceding genes is indicated with double underlining. The operon structures shown were confirmed for the EMP genes by Northern analysis. All other clusters shown represent putative operons. Gene names and corresponding enzyme names: acn, aconitase; adh, alcohol dehydrogenase; acs, acetyl-CoA synthetase; act, acetyl-CoA transferase; amyA, α-amylase; cis1, citrate synthase 1; citE, citrate lyase β chain; fba, FBPA; frdAB, fumarate reductase α and β chains; gaa, glucan-1,4-α-glucosidase; gad, GAD; gap, GAPDH; glgA, glycogen synthase; glgP, (glycogen) phosphorylase; gltX, glutamyl tRNA synthetase; gt, glycosyltransferase; hp, hypothetical protein, hxk, HK; kdgA, KDP(G)A; kdgK, KDGK; mthfs, 5-formyltetrahydrofolate cyclo-ligase; oorABCD, oxoacid:ferredoxin oxidoreductase α, β, γ, and δ chains; orfV, orfX, orfY, and orfZ, hypothetical proteins; pncB, nicotinate phosphoribosyltransferase; pfp, PP_i-PFK; pgk, PGK; ptp, putative transport protein; rfbA, glucose-1-phosphate thymidylyltransferase; rfbB, dTDP-glucose-4,6-dehydratase; rfbC, dTDP-4-dehydrorhamnose-3,5-epimerase; rfbD, dTDP-4-dehydrorhamnose reductase; sdhABCD, succinate dehydrogenase α, β, γ, and δ chains; sucDC, succinyl-CoA synthetase α and β chains; snt, sugar phosphate nucleotidyltransferase; tpi, TIM; tpsp, TPSP; treS/treP, trehalose synthase or trehalose phosphorylase.

The central carbohydrate metabolism in T. tenax. A selection of growth substrates is given at the top; the labels of the different pathways are marked by grey-shaded boxes.