L-valine catabolism in Sporolactobacillus vineae SL153

Best path

bcaP, bkdA, bkdB, bkdC, lpd, acdH, ech, bch, mmsB, mmsA, prpC, prpD, acn, prpB

Rules

Overview: Valine degradation in GapMind is based on MetaCyc pathway L-valine degradation I (link). The other pathways do not produce any fixed carbon and are not included.

• all: valine-transport, BKD, acdH, ech, bch, mmsB, mmsA and propionyl-CoA-degradation
  • Comment: An aminotransferase (not represented) forms 3-methyl-2-oxobutanoate, the decarboxylating alpha-ketoacid dehydrogenase (BKD) forms isobutanoyl-CoA, dehydrogenase acdH forms methylacrylyl-CoA (2-methylprop-2-enoyl-CoA), the hydratase ech forms (S)-3-hydroxy-isobutaonoyl-CoA, a hydrolase forms (S)-3-hydroxy-isobutanoate, a dehydrogenase forms (S)-methylmalonate semialdehyde (2-methyl-3-oxopropanoate), and a decarboxylating dehydrogenase forms propionyl-CoA.
• BKD:
  • bkdA, bkdB, bkdC and lpd
  • or vorA, vorB and vorC
  • or ofoA and ofoB
  • or ofo
  • Comment: These decarboxylating dehydrogenases act on 4-methyl-2-oxopentanoate, 3-methyl-2-oxobutanoate (2-oxoisovalerate) and (S)-3-methyl-2-oxopentanoate and are known as the branched-chain alpha-ketoacid dehydrogenases. They can pass electrons to NAD (EC 1.2.1.25) or to ferredoxin (EC 1.2.7.7). The NAD-dependent enzyme is the sum of three activities: EC 1.2.4.4 (the 4-methyl-2-oxopentanoate dehydrogenase, with transfer to the lipopoyllysine residue of 2.3.1.168) which is itself heteromeric, with alpha and beta subunits; EC 2.3.1.168 (dihydrolipoyllysine-residue (3-methylbutanoyl)transferase); and EC 1.8.1.4 (dihydrolipoyl dehydrogenase, transferring electrons to NAD). The well-characterized ferredoxin-dependent enzymes have 3 subunits (vorABC) or 2 subunits (ofoAB). Genetic data identified a fused ferredoxin-dependent enzyme with just 1 subunit (ofo).
• propionyl-CoA-degradation:
  • prpC, prpD, acn and prpB
  • or prpC, acnD, prpF, acn and prpB
  • or propionyl-CoA-carboxylase, epi and methylmalonyl-CoA-mutase
  • or pco, hpcD, dddA and iolA
  • Comment: In 2-methylcitrate cycle I, propionyl-CoA is combined with oxalacetate (by prpC) to give methylcitrate, dehydrated to cis-2-methylaconitate by prpD, hydrated to (2R,3S)-2-methylisocitrate, and a lyase produces pyruvate and succinate. (We consider succinate as a central intermediate, as most organisms can activate it to succinyl-CoA or can oxidize it to fumarate and convert that to oxaloacetate.) In 2-methylcitrate cycle II, a different dehydratase (acnD) and an isomerase (prpF) replace the dehydratase prpD; acnD dehydrates (2S,3S)-2-methylcitrate to 2-methyl-trans-aconitate, and prpF isomerizes it to cis-2-methylaconitate. In propanoyl CoA degradation I, propionyl-CoA carboxylase forms (S)-methylmalonyl-CoA, methylmalonyl-CoA epimerase forms (R)-methylmalonyl-CoA, and methylmalonyl-CoA mutase forms succinyl-CoA, which is a central metabolite. (Note that methylmalonyl-CoA mutase requires adenosylcobamide, a form of vitamin B12, for activity.) In propanoyl-CoA degradation II: propionyl-CoA is oxidized to acrylyl-CoA by pco, hydrated to 3-hydroxypropionyl-CoA, hydrolzed to 3-hydroxypropionate, oxidized to 3-oxopropionate (malonate semialdehyde), and oxidized to acetyl-CoA and CO2.
• methylmalonyl-CoA-mutase:
  • mcmA
  • or mcm-large and mcm-small
  • Comment: methylmalonyl-CoA mutase has a catalytic domain and a B12-binding domain. These are usually found in the same protein, which we call mcmA. In Metallosphaera and Pyrococcus, the B12-binding domain is a separate subunit. In Propionibacterium and Methylorubrum, there is an additional subunit with a catalytic domain only; this may have a protective role (PMID:14734568) and is not described here. There's also a mcm-interacting GTPase (known as MeaB or YgfD) that loads B12 onto mcm and protects it from inactivation (see PMC4631608); this is not described here. Some fused mcm proteins include a MeaB domain as well (i.e., Q8F222, Q8Y2U5).
• propionyl-CoA-carboxylase:
  • pccA and pccB
  • or pccA1, pccA2 and pccB
  • Comment: propionyl-CoA carboxylase is a heteromer, usually with alpha and beta subunits pccAB. Haloferax mediterranei has a third subunit as well (pccX), which is not described here. Acidianus brierleyi has a diverged pccA split into two pieces.
• valine-transport:
  • livF, livG, livJ, livH and livM
  • or natA, natB, natC, natD and natE
  • or Bap2
  • or brnQ
  • or phtJ
  • or bcaP
  • Comment: Transporters were identified using query: transporter:valine:L-valine:val

47 steps (28 with candidates)

Or see definitions of steps

Step	Description	Best candidate	2nd candidate
bcaP	L-valine uptake transporter BcaP/CitA	RH97_RS02450	RH97_RS05565
bkdA	branched-chain alpha-ketoacid dehydrogenase, E1 component alpha subunit	RH97_RS10575	RH97_RS04120
bkdB	branched-chain alpha-ketoacid dehydrogenase, E1 component beta subunit	RH97_RS10580	RH97_RS04115
bkdC	branched-chain alpha-ketoacid dehydrogenase, E2 component	RH97_RS10585	RH97_RS04110
lpd	branched-chain alpha-ketoacid dehydrogenase, E3 component	RH97_RS04105	RH97_RS10570
acdH	isobutyryl-CoA dehydrogenase	RH97_RS08905
ech	(S)-3-hydroxybutanoyl-CoA hydro-lyase	RH97_RS08930	RH97_RS07390
bch	3-hydroxyisobutyryl-CoA hydrolase	RH97_RS08930
mmsB	3-hydroxyisobutyrate dehydrogenase	RH97_RS02125	RH97_RS06075
mmsA	methylmalonate-semialdehyde dehydrogenase	RH97_RS06770	RH97_RS06550
prpC	2-methylcitrate synthase	RH97_RS00850
prpD	2-methylcitrate dehydratase	RH97_RS04485
acn	(2R,3S)-2-methylcitrate dehydratase	RH97_RS05105
prpB	2-methylisocitrate lyase	RH97_RS04480	RH97_RS04375
Alternative steps:
acnD	2-methylcitrate dehydratase (2-methyl-trans-aconitate forming)	RH97_RS05105
Bap2	L-valine permease Bap2	RH97_RS02150	RH97_RS12570
brnQ	L-valine:cation symporter BrnQ/BraZ/BraB
dddA	3-hydroxypropionate dehydrogenase
epi	methylmalonyl-CoA epimerase
hpcD	3-hydroxypropionyl-CoA dehydratase	RH97_RS08930	RH97_RS07390
iolA	malonate semialdehyde dehydrogenase (CoA-acylating)	RH97_RS06770	RH97_RS06550
livF	L-valine ABC transporter, ATPase component 1 (LivF/BraG)	RH97_RS07250	RH97_RS07245
livG	L-valine ABC transporter, ATPase component 2 (LivG/BraF)	RH97_RS07245	RH97_RS08020
livH	L-valine ABC transporter, permease component 1 (LivH/BraD)	RH97_RS07235
livJ	L-valine ABC transporter, substrate-binding component (LivJ/LivK/BraC/BraC3)	RH97_RS07230
livM	L-valine ABC transporter, permease component 2 (LivM/BraE)	RH97_RS07240
mcm-large	methylmalonyl-CoA mutase, large (catalytic) subunit
mcm-small	methylmalonyl-CoA mutase, small (adenosylcobamide-binding) subunit
mcmA	methylmalonyl-CoA mutase, fused catalytic and adenosylcobamide-binding components
natA	L-valine ABC transporter, ATPase component 1 (NatA)	RH97_RS07245	RH97_RS07250
natB	L-valine ABC transporter, substrate-binding component NatB
natC	L-valine ABC transporter, permease component 1 (NatC)
natD	L-valine ABC transporter, permease component 2 (NatD)	RH97_RS07235
natE	L-valine ABC transporter, ATPase component 2 (NatE)	RH97_RS07250	RH97_RS08365
ofo	branched-chain alpha-ketoacid:ferredoxin oxidoreductase, fused
ofoA	branched-chain alpha-ketoacid:ferredoxin oxidoreductase, alpha subunit OfoA
ofoB	branched-chain alpha-ketoacid:ferredoxin oxidoreductase, beta subunit OfoB
pccA	propionyl-CoA carboxylase, alpha subunit	RH97_RS08700	RH97_RS04065
pccA1	propionyl-CoA carboxylase, biotin carboxyl carrier subunit	RH97_RS08700	RH97_RS04065
pccA2	propionyl-CoA carboxylase, biotin carboxylase subunit
pccB	propionyl-CoA carboxylase, beta subunit
pco	propanyl-CoA oxidase
phtJ	L-valine uptake permease PhtJ
prpF	methylaconitate isomerase
vorA	branched-chain alpha-ketoacid:ferredoxin oxidoreductase, alpha subunit VorA
vorB	branched-chain alpha-ketoacid:ferredoxin oxidoreductase, beta subunit VorB
vorC	branched-chain alpha-ketoacid:ferredoxin oxidoreductase, gamma subunit VorC

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.