L-phenylalanine catabolism in Rhodomicrobium vannielii ATCC 17100

Best path

livF, livG, livH, livM, livJ, ARO8, iorAB, padB, padC, padD, padG, padI, padE, padF, padH, bcrA, bcrB, bcrC, bcrD, dch, had, oah, pimB, gcdH, ech, fadB, atoB

Rules

Overview: Phenylalanine utilization in GapMind is based on MetaCyc pathway L-phenylalanine degradation I (aerobic, via tyrosine, link), pathway II (anaerobic, via phenylacetaldehyde dehydrogenase, link), 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.)

• all:
  • phenylalanine-transport, ARO8, phenylpyruvate-fd-oxidoreductase and phenylacetyl-CoA-degradation
  • or phenylalanine-transport, ARO8, phenylpyruvate-decarboxylase, pad-dh and phenylacetate-degradation
  • or phenylalanine-transport, ARO8, phenylpyruvate-decarboxylase, pfor and phenylacetate-degradation
  • or phenylalanine-transport, PAH, PCBD, QDPR and tyrosine-degradation
  • Comment: 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. In the anaerobic pathway, the transaminase ARO8 forms phenylpyruvate, a carboxy-lyase forms phenylacetaldehyde, and a dehydrogenase (pad-dh) forms phenylacetate Or, in a variation on the anaerobic pathway, the phenylacetaldehyde is oxidized to phenylacetate by phenylacetaldehyde:ferredoxin oxidoreductase (pfor). In the aerobic pathway, PAH forms tyrosine and hydroxylates its tetrahydropterin co-substrate; the tetrahydropterin is regenerated by dehydratase PCBD and reductase QDPR.
• phenylpyruvate-fd-oxidoreductase:
  • iorA and iorB
  • or iorAB
  • Comment: 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-decarboxylase:
  • ARO10
  • or PPDCalpha and PPDCbeta
  • Comment: Phenylpyruvate can be decarboxylated to phenylacetaldehyde by the typical homomeric enzyme, or by a heterodimer reported in Streptomyces virginiae (see PMID:28719183)
• phenylacetyl-CoA-degradation:
  • paaA, paaB, paaC, paaE, paaG, paaZ1, paaZ2, paaJ1, paaF, paaH and paaJ2
  • or phenylacetyl-CoA-dehydrogenase, phenylglyoxylate-dehydrogenase and benzoyl-CoA-degradation
  • Comment: In the aerobic pathway, oxygen-dependent 1,2-epoxidase (PaaABCE) converts phenylacetyl-CoA to 1,2-epoxyphenylacetyl-CoA, which spontaenously rearranges to 2-(oxepinyl)acetyl-CoA; isomerase PaaG forms 2-oxepin-2(3H)-ylideneacetyl-CoA ("oxepin-CoA"); a ring-opening hydrolase forms 3-oxo-5,6-didehydrosuberyl-CoA semialdehyde; a dehydrogenase forms 3-oxo-5,6-didehydrosuberyl-CoA; thiolase PaaJ forms cis-3,4-didehydroadipyl-CoA (and acetyl-CoA); isomerase PaaG forms trans-2,3-didehydroadipyl-CoA; hydratase PaaF forms (3S)-hydroxyadipyl-CoA; dehydrogenase PaaH forms 3-oxoadipyl-CoA, and thiolase PaaJ forms succinyl-CoA and acetyl-CoA. (The role of PaaG is described in PMID:31689071 and differs slightly from MetaCyc.) In the anaerobic pathway, a dehydrogenase forms phenylglyoxyl-CoA, a hydrolase forms phenylglyoxylate (this step is not linked to sequence but is likely provided by the phenylglyoxylyl-CoA dehydrogenase, see PMID:10336636), and another dehydrogenase forms benzoyl-CoA and CO2. In principle, this pathway could occur aerobically, so GapMind includes aerobic pathways for degrading the benzoyl-CoA.
• phenylacetate-degradation: paaK and phenylacetyl-CoA-degradation
  • Comment: Phenylacetate is activated to phenylacetyl-CoA by paaK
• benzoyl-CoA-degradation:
  • benzoyl-CoA-reductase, dch, had, oah, pimB and glutaryl-CoA-degradation
  • or benzoyl-CoA-reductase, Ch1CoA, badK, badH, badI, pimD, pimC, pimF and glutaryl-CoA-degradation
  • or boxA, boxB, boxC, boxD, paaF, paaH and paaJ2
  • Comment: Benzoyl-CoA can be degraded anaerobically (link) by reduction to cyclohex-1,5-diene-1-carbonyl-CoA, followed by hydratase (dch) to 6-hydroxycyclohex-1-ene-1-carbonyl-CoA, a dehydrogenase to 6-oxocyclohex-1-ene-1-carbonyl-CoA, a hydrolase to 2-hydroxy-6-oxocycloheane-1-carbonyl-CoA, a ring-opening hydrolase to 3-hydroxypimeloyl-CoA [the last two steps are both catalyzed by oah], a dehydrogenase to 3-oxopimeloyl-CoA [not linked to sequence and omitted], and an acetyltransferase to glutaryl-CoA and acetyl-CoA. Alternatively, after reduction to cyclohex-1,5-diene-1-carbonyl-CoA, Ch1CoA can further reduce it to cyclohex-1-ene-1-carboxyl-CoA (link), followed by hydration to 2-hydroxy-cyclohexane-1-carbonyl-CoA, oxidation to 2-ketocyclohexane-1-carbonyl-CoA, cleavage by a ring-opening hydrolase to pimeloyl-CoA, oxidation to 2,3-didehydropimeloyl-CoA, hydration to 3-hydroxypimeloyl-C, oxidation to 3-oxopimeloyl-CoA and cleavage by a thiolase to glutaryl-CoA and acetyl-CoA. Benzoyl-CoA degradation can be degraded aerobically (link) by an epoxidase (boxAB) that forms 2,3-epoxy-2-3-dihydrobenzoyl-CoA; a dihydrolase forms cis-3,4-dihydroadipyl-CoA semialdehyde and formate; a dehydrogenase forms cis-3,4-dehydroadipyl-CoA; and an unknown isomerase forms trans-2,3-dehydroadipyl-CoA. This is converted to succinyl-CoA as in the anaerobic pathway (paaF, paaH, and paaJ2).
• phenylglyoxylate-dehydrogenase: padG, padI, padE, padF and padH
• phenylacetyl-CoA-dehydrogenase: padB, padC and padD
• glutaryl-CoA-degradation: gcdH, ech, fadB and atoB
  • Comment: In MetaCyc pathway glutaryl-CoA degradation (link), glutaryl-CoA is oxidized to (E)-glutaconyl-CoA and oxidatively decarboxylated to crotonyl-CoA (both by the same enzyme), hydrated to 3-hydroxybutanoyl-CoA, oxidized to acetoacetyl-CoA, and cleaved to two acetyl-CoA.
• benzoyl-CoA-reductase:
  • bcrA, bcrB, bcrC and bcrD
  • or bamB, bamC, bamD, bamE, bamF, bamG, bamH and bamI
  • Comment: Benzoyl-CoA reduction is energetically unfavorable. There are two classes of reductases: class I enzymes (bcrABCD) use ATP to drive the reaction, while class II enzymes (bamBCDEFGHI) are thought to us an electron bifurcation. SYN_02587 (Q2LQN9) from Syntrophus aciditrophicus, which can oxidize cyclohex-1,5-diene-1-carbonyl-CoA to benzoyl-CoA, is not included because it seems to lack a mechanism to drive benzoyl-CoA reduction.
• tyrosine-degradation: HPD, hmgA, maiA, fahA and acetoacetate-degradation
  • Comment: In pathway I, an aminotransferase (not represented) forms 3-(4-hydroxyphenyl)pyruvate, dioxygenase HPD forms homogentisate, another oxygenase forms 4-maleyl-acetoacetate, an isomerase forms 4-fumaryl-acetoacetate, and a hydrolase yields acetoacetate and fumarate. (Fumarate is part of the TCA cycle so its catabolism is not described.)
• acetoacetate-degradation: acetoacetate-activation and atoB
  • Comment: The acetoacetate is activated to acetoacetyl-CoA, and cleaved by acetyl-CoA acetyltransferase, giving two acetyl-CoA.
• acetoacetate-activation:
  • atoA and atoD
  • or aacS
  • Comment: acetyl-CoA:acetoacetyl-CoA transferase (sometimes given EC 2.8.3.9 or EC 2.8.3.8) or succinyl-CoA:acetoacetyl-CoA transferase (EC 2.8.3.5, also known as 3-oxoacid CoA-transferase) can activate acetoacetate. These have an A and B subunit. Alternatively, an ATP-dependent ligase (aacS) can activate acetoacetate (EC 6.2.1.16).
• phenylalanine-transport:
  • livF, livG, livH, livM and livJ
  • or aroP
  • Comment: Transporters were identified using query: transporter:phenylalanine:L-phenylalanine:phe

76 steps (41 with candidates)

Or see definitions of steps

Step	Description	Best candidate	2nd candidate
livF	L-phenylalanine ABC transporter, ATPase component 1 (LivF)	RVAN_RS04105	RVAN_RS14875
livG	L-phenylalanine ABC transporter, ATPase component 2 (LivG)	RVAN_RS14870	RVAN_RS04110
livH	L-phenylalanine ABC transporter, permease component 1 (LivH)	RVAN_RS04120	RVAN_RS14865
livM	L-phenylalanine ABC transporter, permease component 2 (LivM)	RVAN_RS19490	RVAN_RS14870
livJ	L-phenylalanine ABC transporter, substrate-binding component LivJ/LivK	RVAN_RS04095
ARO8	L-phenylalanine transaminase	RVAN_RS06420	RVAN_RS14850
iorAB	phenylpyruvate:ferredoxin oxidoreductase, fused IorA/IorB	RVAN_RS03470
padB	phenylacetyl-CoA dehydrogenase, PadB subunit
padC	phenylacetyl-CoA dehydrogenase, PadC subunit	RVAN_RS02925
padD	phenylacetyl-CoA dehydrogenase, PadD subunit
padG	phenylglyoxylate dehydrogenase, alpha subunit
padI	phenylglyoxylate dehydrogenase, beta subunit
padE	phenylglyoxylate dehydrogenase, gamma subunit
padF	phenylglyoxylate dehydrogenase, delta subunit
padH	phenylglyoxylate dehydrogenase, epsilon subunit
bcrA	ATP-dependent benzoyl-CoA reductase, alpha subunit	RVAN_RS00195	RVAN_RS18120
bcrB	ATP-dependent benzoyl-CoA reductase, beta subunit	RVAN_RS00190
bcrC	ATP-dependent benzoyl-CoA reductase, gamma subunit	RVAN_RS00185
bcrD	ATP-dependent benzoyl-CoA reductase, delta subunit	RVAN_RS00200	RVAN_RS18120
dch	cyclohexa-1,5-diene-1-carboxyl-CoA hydratase	RVAN_RS00180	RVAN_RS17115
had	6-hydroxycyclohex-1-ene-1-carbonyl-CoA dehydrogenase	RVAN_RS00170
oah	6-oxocyclohex-1-ene-1-carbonyl-CoA hydratase	RVAN_RS00175	RVAN_RS11250
pimB	3-oxopimeloyl-CoA:CoA acetyltransferase	RVAN_RS00115	RVAN_RS02760
gcdH	glutaryl-CoA dehydrogenase	RVAN_RS09295	RVAN_RS03505
ech	(S)-3-hydroxybutanoyl-CoA hydro-lyase	RVAN_RS11250	RVAN_RS17115
fadB	(S)-3-hydroxybutanoyl-CoA dehydrogenase	RVAN_RS14570	RVAN_RS02765
atoB	acetyl-CoA C-acetyltransferase	RVAN_RS00115	RVAN_RS17080
Alternative steps:
aacS	acetoacetyl-CoA synthetase	RVAN_RS00550	RVAN_RS18025
ARO10	phenylpyruvate decarboxylase
aroP	L-phenylalanine:H+ symporter AroP
atoA	acetoacetyl-CoA transferase, A subunit
atoD	acetoacetyl-CoA transferase, B subunit
badH	2-hydroxy-cyclohexanecarboxyl-CoA dehydrogenase	RVAN_RS04710	RVAN_RS13210
badI	2-ketocyclohexanecarboxyl-CoA hydrolase	RVAN_RS11250	RVAN_RS00175
badK	cyclohex-1-ene-1-carboxyl-CoA hydratase	RVAN_RS11250	RVAN_RS17115
bamB	class II benzoyl-CoA reductase, BamB subunit
bamC	class II benzoyl-CoA reductase, BamC subunit
bamD	class II benzoyl-CoA reductase, BamD subunit
bamE	class II benzoyl-CoA reductase, BamE subunit
bamF	class II benzoyl-CoA reductase, BamF subunit
bamG	class II benzoyl-CoA reductase, BamG subunit
bamH	class II benzoyl-CoA reductase, BamH subunit	RVAN_RS18455
bamI	class II benzoyl-CoA reductase, BamI subunit
boxA	benzoyl-CoA epoxidase, subunit A
boxB	benzoyl-CoA epoxidase, subunit B
boxC	2,3-epoxybenzoyl-CoA dihydrolase
boxD	3,4-dehydroadipyl-CoA semialdehyde dehydrogenase
Ch1CoA	cyclohex-1-ene-1-carbonyl-CoA dehydrogenase	RVAN_RS17085	RVAN_RS03475
fahA	fumarylacetoacetate hydrolase	RVAN_RS01040
hmgA	homogentisate dioxygenase
HPD	4-hydroxyphenylpyruvate dioxygenase
iorA	phenylpyruvate:ferredoxin oxidoreductase, IorA subunit
iorB	phenylpyruvate:ferredoxin oxidoreductase, IorB subunit
maiA	maleylacetoacetate isomerase
paaA	phenylacetyl-CoA 1,2-epoxidase, subunit A
paaB	phenylacetyl-CoA 1,2-epoxidase, subunit B
paaC	phenylacetyl-CoA 1,2-epoxidase, subunit C
paaE	phenylacetyl-CoA 1,2-epoxidase, subunit E
paaF	2,3-dehydroadipyl-CoA hydratase	RVAN_RS17115	RVAN_RS11250
paaG	1,2-epoxyphenylacetyl-CoA isomerase / 2-(oxepinyl)acetyl-CoA isomerase / didehydroadipyl-CoA isomerase	RVAN_RS11250	RVAN_RS18060
paaH	3-hydroxyadipyl-CoA dehydrogenase	RVAN_RS14570	RVAN_RS02765
paaJ1	3-oxo-5,6-dehydrosuberyl-CoA thiolase	RVAN_RS00225	RVAN_RS00115
paaJ2	3-oxoadipyl-CoA thiolase	RVAN_RS00225	RVAN_RS00115
paaK	phenylacetate-CoA ligase	RVAN_RS04370
paaZ1	oxepin-CoA hydrolase	RVAN_RS09930	RVAN_RS18060
paaZ2	3-oxo-5,6-didehydrosuberyl-CoA semialdehyde dehydrogenase
pad-dh	phenylacetaldehyde dehydrogenase	RVAN_RS09190	RVAN_RS07805
PAH	phenylalanine 4-monooxygenase
PCBD	pterin-4-alpha-carbinoalamine dehydratase	RVAN_RS15310
pfor	phenylacetaldeyde:ferredoxin oxidoreductase
pimC	pimeloyl-CoA dehydrogenase, small subunit
pimD	pimeloyl-CoA dehydrogenase, large subunit	RVAN_RS15420
pimF	6-carboxyhex-2-enoyl-CoA hydratase	RVAN_RS14570	RVAN_RS02765
PPDCalpha	phenylpyruvate decarboxylase, alpha subunit	RVAN_RS06700
PPDCbeta	phenylpyruvate decarboxylase, beta subunit	RVAN_RS06695
QDPR	6,7-dihydropteridine reductase	RVAN_RS17515

Confidence: high confidence medium confidence low confidence
transporter – transporters and PTS systems are shaded because predicting their specificity is particularly challenging.

This GapMind analysis is from Sep 24 2021. The underlying query database was built on Sep 17 2021.