As text, or see rules and steps
# L-arabinose utilization in GapMind is based on MetaCyc pathways # L-arabinose degradation I, via xylulose 5-phosphate (metacyc:ARABCAT-PWY); # III, oxidation to 2-oxoglutarate (metacyc:PWY-5517); # and IV, via glycolaldehyde (metacyc:PWY-7295). # Pathway II via xylitol and xylulose is not represented in GapMind # because it is not reported in prokaryotes (metacyc:PWY-5515). # ABC transporters: # GguAB-ChvE from Agrobacterium tumefaciens/radiobacter # AraFGH from E. coli # AraSTUV from Sulfolobus solfataricus # XacGHIJKJ from Haloferax volcanii # XylFGH from Sulfolobus acidocaldarius gguA L-arabinose ABC transporter, ATPase component GguA curated:TCDB::O05176 gguB L-arabinose ABC transporter, permease component GguB curated:TCDB::O05177 # The related protein sbpA (P54083) binds arabinose chvE L-arabinose ABC transporter, substrate-binding component ChvE curated:TCDB::P25548 ignore:SwissProt::P54083 # Transporters were identified using # query: transporter:arabinose:L-arabinose:L-arabinofuranose:L-arabinopyranose:beta-L-arabinose:CPD-12045:CPD-12046 arabinose-transport: gguA gguB chvE araF L-arabinose ABC transporter, substrate-binding component AraF curated:SwissProt::P02924 araG L-arabinose ABC transporter, ATPase component AraG curated:SwissProt::P0AAF3 araH L-arabinose ABC transporter, permease component AraH curated:CharProtDB::CH_014278 arabinose-transport: araF araG araH araS L-arabinose ABC transporter, substrate-binding component AraS curated:TCDB::Q97UF5 araT L-arabinose ABC transporter, permease component 1 (AraT) curated:TCDB::Q97UF4 araU L-arabinose ABC transporter, permease component 2 (AraU) curated:TCDB::Q97UF3 araV L-arabinose ABC transporter, ATPase component AraV curated:TCDB::Q97UF2 arabinose-transport: araS araT araU araV xacG L-arabinose ABC transporter, substrate-binding component XacG uniprot:D4GP35 xacH L-arabinose ABC transporter, permease component 1 (XacH) uniprot:D4GP36 xacI L-arabinose ABC transporter, permease component 2 (XacI) uniprot:D4GP37 xacJ L-arabinose ABC transporter, ATPase component 1 (XacJ) uniprot:D4GP38 xacK L-arabinose ABC transporter, ATPase component 2 (XacK) uniprot:D4GP39 arabinose-transport: xacG xacH xacI xacJ xacK xylFsa L-arabinose ABC transporter, substrate-binding component XylF uniprot:Q4J710 xylGsa L-arabinose ABC transporter, ATPase component XylG uniprot:P0DTT6 xylHsa L-arabinose ABC transporter, permease component XylH uniprot:Q4J711 arabinose-transport: xylFsa xylGsa xylHsa # Rodionov et al proposed that the Shewanella arabinose transporter is araUVWZ; this was confirmed # by fitness data for Shewana3_2073:2076 araUsh L-arabinose ABC transporter, substrate-binding component AraU(Sh) uniprot:A0KWY4 araVsh L-arabinose ABC transporter, ATPase component AraV(Sh) uniprot:A0KWY5 araWsh L-arabinose ABC transporter, permease component 1 AraW(Sh) uniprot:A0KWY6 araZsh L-arabinose ABC transporter, permease component 2 AraZ(Sh) uniprot:A0KWY7 arabinose-transport: araUsh araVsh araWsh araZsh # homomeric transporters araE L-arabinose:H+ symporter curated:SwissProt::P0AE24 curated:SwissProt::P96710 curated:TCDB::C4B4V9 arabinose-transport: araE # In the RB-TnSeq data, BT0355 is very important for L-arabinose utilization, and this does # not seem to be a polar effect (the effect is found on both strands). # In contrast, PMC5061871 reported a subtle effect of deleting BT0355 on L-arabinose utilization, # but found that it was required for arabinobiose utilization. BT0355 L-arabinose:Na+ symporter uniprot:Q8AAV7 arabinose-transport: BT0355 # Echvi_1880 is specifically important for L-arabinose utilization Echvi_1880 L-arabinose:Na+ symporter uniprot:L0FZT5 arabinose-transport: Echvi_1880 # Ignore various arabinose exporters: # yhhS, yfcJ, setC, ybdA, ydeA, ynfM, kgtP from E. coli; SotA from Erwinia; # CmlA/MdfA from Pseudomonas aeruginosa # # Ignore AraNPQ-MsmX from B. subtilis, which is sometimes annotated as an arabinose transporter, # but genetic studies suggests that it is involved in the transport of oligosaccharides of arabinose # only (see PMC2950484) araA L-arabinose isomerase EC:5.3.1.4 # BT0350 (Q8AAW2) is similar to the L-ribulokinase of Corynebacterium glutamicum (PMC2687266; C4B4W2) # and is specifically improtant during growth on L-arabinose. araB ribulokinase EC:2.7.1.16 uniprot:C4B4W2 uniprot:Q8AAW2 araD L-ribulose-5-phosphate epimerase EC:5.1.3.4 # araABD is pathway I. # In pathway I, isomerase araA forms L-ribulose, kinase # araB forms ribulose 5-phosphate, and epimerase araD # forms D-xylulose 5-phosphate, # which is an intermediate in the pentose phosphate pathway. all: arabinose-transport araA araB araD xacB L-arabinose 1-dehydrogenase EC:1.1.1.376 EC:1.1.1.46 # SMc00883 (Q92RN9) is specifically important for L-arabinose utilization and does not appear polar. # (It has a vague annotation in SwissProt.) # Similarly for Ac3H11_615 (A0A165IRV8) xacC L-arabinono-1,4-lactonase EC:3.1.1.15 uniprot:Q92RN9 uniprot:A0A165IRV8 ignore:SwissProt::Q92RN9 # The function of Q92RP0 seems to be unknown so ignore it xacD L-arabinonate dehydratase EC:4.2.1.25 ignore:SwissProt::Q92RP0 xacE 2-dehydro-3-deoxy-L-arabinonate dehydratase EC:4.2.1.43 xacF alpha-ketoglutarate semialdehyde dehydrogenase EC:1.2.1.26 # In pathway III, the 1-dehydrogenase xacB # (which acts on the furanose form, not the usual pyranose form?) # forms arabino-1,4-lactone, lactonase xacC forms arbinonate, two # dehydratases form 2-dehydro-3-deoxy-L-arabinonate and 2,5-dioxopentanonate (α-ketoglutarate semialdehyde), # and dehydrogenase xacF forms 2-oxoglutarate, which is an intermediate in the TCA cycle. # (Fitness data suggests that L-arabinose 1-epimerase or mutarotase is also involved, # perhaps in creating the correct epimer for the 1-dehydrogenase, but # is not included in GapMind.) all: arabinose-transport xacB xacC xacD xacE xacF # gyaR = glyoxylate reductase / glycolate dehydrogenase # glcB = malate synthase import xylose.steps:glycolaldehyde-dehydrogenase gyaR glcB # Q97U28 is the same protein but with 14 more N-terminal a.a., and is annotated with 4.1.2.55 only. # And a similar enzyme from S. acidcaldarius is thought to perform this reaction as well (PMC2962468) KDG-aldolase 2-dehydro-3-deoxy-L-arabinonate aldolase EC:4.1.2.18 ignore:BRENDA::Q97U28 curated:BRENDA::Q4JC35 # Pathway IV begins as in pathway III, to # 2-dehydro-3-deoxy-L-arabinonate, followed by KDG aldolase to # pyruvate and glycolaldehyde; the glycolaldehyde is oxidized to # glycolate and then to glyoxylate, and combined with acetyl-CoA by # malate synthase, which is a TCA cycle intermediate. # (Other pathways for glyxoylate assimilation are known but are not # represented here.) all: arabinose-transport xacB xacC xacD KDG-aldolase glycolaldehyde-dehydrogenase gyaR glcB
Each pathway is defined by a set of rules based on individual steps or genes. Candidates for each step are identified by using ublast (a fast alternative to protein BLAST) against a database of manually-curated proteins (most of which are experimentally characterized) or by using HMMer with enzyme models (usually from TIGRFam). Ublast hits may be split across two different proteins.
A candidate for a step is "high confidence" if either:
Otherwise, a candidate is "medium confidence" if either:
Other blast hits with at least 50% coverage are "low confidence."
Steps with no high- or medium-confidence candidates may be considered "gaps." For the typical bacterium that can make all 20 amino acids, there are 1-2 gaps in amino acid biosynthesis pathways. For diverse bacteria and archaea that can utilize a carbon source, there is a complete high-confidence catabolic pathway (including a transporter) just 38% of the time, and there is a complete medium-confidence pathway 63% of the time. Gaps may be due to:
GapMind relies on the predicted proteins in the genome and does not search the six-frame translation. In most cases, you can search the six-frame translation by clicking on links to Curated BLAST for each step definition (in the per-step page).
For more information, see:
If you notice any errors or omissions in the step descriptions, or any questionable results, please let us know
by Morgan Price, Arkin group, Lawrence Berkeley National Laboratory