As text, or see rules and steps
# Phenylalanine utilization in GapMind is based on MetaCyc pathway # L-phenylalanine degradation I (aerobic, via tyrosine, metacyc:PHENYLALANINE-DEG1-PWY), # pathway II (anaerobic, via phenylacetaldehyde dehydrogenase, metacyc:ANAPHENOXI-PWY), # degradation via phenylpyruvate:ferredoxin oxidoreductase (PMC3346364), # or degradation via phenylacetaldehyde:ferredoxin oxidoreductase (PMID:24214948). # (MetaCyc describes additional pathways, but they do not result in carbon # incorporation or are not reported in prokaryotes, so they are not included in GapMind.) # In E. coli, the ABC transporter livFGHMJ or livFGHMK transports phenylalanine. # livJ and livK are alternate substrate binding proteins that are similar to each other. # # A related system in Pseudomonas fluorescens FW300-N2E2 is also important for phenylalanine utlization: # Pf6N2E2_2921 = livK = A0A160A0J6; Pf6N2E2_2923 = livH = A0A0D9B2B6; Pf6N2E2_2924 = livM = A0A159ZYE0; # Pf6N2E2_2925 = livG = A0A159ZWS6; Pf6N2E2_2926 = livF = A0A159ZWL6). # # Ignored the orthologs in Pseudomonas aeruginosa (the bra system), which transports various # amino acids and might transport phenylalanine. # # A related system in Acidovorax sp. GW101-3H11 also transports phenylalanine: # LivF = Ac3H11_1692 (A0A165KC78), LivG = Ac3H11_1693 (A0A165KC86), # LivJ = Ac3H11_2396 (A0A165KTD4; not near the other components, but cofit), # LivH = Ac3H11_1695 (A0A165KC95), LivM = Ac3H11_1694 (A0A165KER0). livF L-phenylalanine ABC transporter, ATPase component 1 (LivF) curated:CharProtDB::CH_003736 uniprot:A0A159ZWL6 ignore:TCDB::P21630 uniprot:A0A165KC78 livG L-phenylalanine ABC transporter, ATPase component 2 (LivG) curated:TCDB::P0A9S7 uniprot:A0A159ZWS6 ignore:TCDB::P21629 uniprot:A0A165KC86 livH L-phenylalanine ABC transporter, permease component 1 (LivH) curated:ecocyc::LIVH-MONOMER uniprot:A0A0D9B2B6 ignore:TCDB::P21627 uniprot:A0A165KC95 livM L-phenylalanine ABC transporter, permease component 2 (LivM) curated:SwissProt::P22729 uniprot:A0A159ZYE0 ignore:TCDB::P21628 uniprot:A0A165KER0 livJ L-phenylalanine ABC transporter, substrate-binding component LivJ/LivK curated:CharProtDB::CH_107418 curated:TCDB::P0AD96 uniprot:A0A160A0J6 ignore:SwissProt::P21175 uniprot:A0A165KTD4 # Transporters were identified using # query: transporter:phenylalanine:L-phenylalanine:phe phenylalanine-transport: livF livG livH livM livJ # RR42_RS33495 from Cupriavidus basilensis FW507-4G11 (A0A0C4YP23) is the phenylalanine transporter. # Ignore A2RMP5, an ortholog from another Lactococcus. aroP L-phenylalanine:H+ symporter AroP curated:TCDB::P15993 curated:TCDB::F2HN33 curated:TCDB::P24207 curated:TCDB::Q2VQZ4 curated:TCDB::Q46065 uniprot:A0A0C4YP23 ignore:SwissProt::A2RMP5 phenylalanine-transport: aroP # non-specific eukaryotic transporters (i.e., Q01650) and the related serine/threonine exchanger SteT were excluded # amino acid exporters such as yddG were excluded # acetoacetate is an intermediate in tyrosine degradation import leucine.steps:acetoacetate-degradation # tyrosine is an intermediate in phenylalanine degradation import tyrosine.steps:tyrosine-degradation # phenylacetate is an intermediate in phenylalanine degradation import phenylacetate.steps:phenylacetate-degradation phenylacetyl-CoA-degradation # Several pathways involve transamination to phenylpyruvate ARO8 L-phenylalanine transaminase EC:2.6.1.1 EC:2.6.1.27 EC:2.6.1.57 ignore:BRENDA::Q845W8 ignore:BRENDA::A0A060PQX5 ignore:SwissProt::P52878 ignore:BRENDA::O57946 ARO10 phenylpyruvate decarboxylase EC:4.1.1.43 ignore:BRENDA::A0A222AKA3 # The alpha subunit is MF179145 = A0A222AKA3 (which appears in BRENDA) PPDCalpha phenylpyruvate decarboxylase, alpha subunit curated:BRENDA::A0A222AKA3 # The beta subunit is not curated but is MF179146 = ASO76824.1, identical in sequence to G1UHX5 PPDCbeta phenylpyruvate decarboxylase, beta subunit uniprot:G1UHX5 # Phenylpyruvate can be decarboxylated to phenylacetaldehyde by the typical # homomeric enzyme, or by a heterodimer reported in Streptomyces virginiae # (see PMID:28719183) phenylpyruvate-decarboxylase: ARO10 phenylpyruvate-decarboxylase: PPDCalpha PPDCbeta iorA phenylpyruvate:ferredoxin oxidoreductase, IorA subunit curated:BRENDA::O07835 curated:BRENDA::Q6LZB6 curated:BRENDA::Q6M0F5 curated:SwissProt::P80910 iorB phenylpyruvate:ferredoxin oxidoreductase, IorB subunit curated:BRENDA::O07836 curated:BRENDA::Q6LZB5 curated:BRENDA::Q6M0F6 curated:SwissProt::P80911 # A fused enzyme is described in Phaeobacter gallaeciensis (ior1 = A9ERV7 = I7EJ57, see PMC3346364). iorAB phenylpyruvate:ferredoxin oxidoreductase, fused IorA/IorB curated:reanno::BFirm:BPHYT_RS02015 curated:reanno::Marino:GFF880 uniprot:I7EJ57 # This enzyme is usually known as # indolepyruvate:ferredoxin oxidoreductase, but it acts on # phenylpyruvate as well, forming phenylacetyl-CoA (PMID:8206994). # Phenylpyruvate:ferredoxin oxidoreductase has both heterodimeric # (iorA/iorB) and fused (iorAB) forms. phenylpyruvate-fd-oxidoreductase: iorA iorB phenylpyruvate-fd-oxidoreductase: iorAB # Phenylalanine can be catabolized via transaminase ARO8, which forms # phenylpyruvate (also known as 3-phenyl-2-oxo-propanoate), # and phenylpyruvate:ferredoxin oxidoreductase, which forms # phenylacetyl-CoA. all: phenylalanine-transport ARO8 phenylpyruvate-fd-oxidoreductase phenylacetyl-CoA-degradation pad-dh phenylacetaldehyde dehydrogenase EC:1.2.1.39 # In the anaerobic pathway, the transaminase ARO8 forms # phenylpyruvate, a carboxy-lyase forms phenylacetaldehyde, # and a dehydrogenase (pad-dh) forms phenylacetate all: phenylalanine-transport ARO8 phenylpyruvate-decarboxylase pad-dh phenylacetate-degradation # This enzyme is ebA5005 = Q5P143. It runs in parallel with a # phenylacetaldehyde dehydrogenase (PMID:24214948). pfor phenylacetaldeyde:ferredoxin oxidoreductase EC:1.2.7.5 uniprot:Q5P143 # Or, in a variation on the anaerobic pathway, the phenylacetaldehyde is oxidized to phenylacetate # by phenylacetaldehyde:ferredoxin oxidoreductase (pfor). all: phenylalanine-transport ARO8 phenylpyruvate-decarboxylase pfor phenylacetate-degradation PAH phenylalanine 4-monooxygenase EC:1.14.16.1 PCBD pterin-4-alpha-carbinoalamine dehydratase EC:4.2.1.96 # In Pseudomonas, the cosubstrate of PAH is # (6R)-L-threo-5,6,7,8-tetrahydroneopterin, also known as # tetrahydromonapterin; in Chlorobaculum tepidum, it is # (6R)-L-threo-5,6,7,8-tetrahydrobiopterin. # EC:1.5.1.34 describes tetrahydrobiopterin reductases, # while EC:1.5.1.50 describes bacterial dihydromonapterin reductases (folM in E. coli) QDPR 6,7-dihydropteridine reductase EC:1.5.1.34 EC:1.5.1.50 ignore:SwissProt::P26353 ignore:BRENDA::P15888 ignore:SwissProt::Q01234 # In the aerobic pathway, PAH forms tyrosine and hydroxylates its # tetrahydropterin co-substrate; the tetrahydropterin is regenerated # by dehydratase PCBD and reductase QDPR. all: phenylalanine-transport PAH PCBD QDPR tyrosine-degradation
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