Finding step mglA for trehalose catabolism in Escherichia coli BW25113
4 candidates for mglA: glucose ABC transporter, ATP-binding component (MglA)
Confidence: high confidence medium confidence low confidence
transporter – transporters and PTS systems are shaded because predicting their specificity is particularly challenging.
GapMind searches the predicted proteins for candidates by using ublast (a fast alternative to protein BLAST) to find similarities to characterized proteins or by using HMMer to find similarities to enzyme models (usually from TIGRFams). For alignments to characterized proteins (from ublast), scores of 44 bits correspond to an expectation value (E) of about 0.001.
Also see fitness data for the candidates
Definition of step mglA
- Ignore hits to D4GPW3 when looking for 'other' hits (Glucose import ATP-binding protein TsgD13; EC 7.5.2.-)
- Curated sequence G4FGN3: Monosaccharide-transporting ATPase, component of Glucose porter. Also bind xylose (Boucher and Noll 2011). Induced by glucose (Frock et al. 2012). Directly regulated by glucose-responsive regulator GluR
- Curated sequence O05176: GguA aka ATU2347 aka AGR_C_4264, component of Multiple sugar (arabinose, xylose, galactose, glucose, fucose) putative porter
- Curated sequence P0AAG8: Galactose/methyl galactoside import ATP-binding protein MglA aka B2149, component of Galactose/glucose (methyl galactoside) porter. D-galactose/methyl-galactoside ABC transporter ATP binding subunit. D-galactose/methyl-galactoside ABC transporter ATP binding subunit
- Curated sequence GFF3641: glucose transporter, ATPase component
- Ignore hits to P23924 when looking for 'other' hits (Galactose/methyl galactoside import ATP-binding protein MglA; EC 7.5.2.11)
- Comment: mglABC-like ABC transporters, from E. coli, Haloferax, Thermotoga, Agrobacterium, and Phaeobacter. But in Haloferax, only two components are known; there is a SBP nearby but also a second permease. So mark TSGDD_HALVD / D4GPW3 and D4GPW2 as ignore. Also, there is one paper about the Salmonella ortholog of mglABC; not clear if that transports glucose or not, so ignore that as well (P23924).
Or cluster all characterized mglA proteins
This GapMind analysis is from Apr 09 2024. The underlying query database was built on Sep 17 2021.
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About GapMind
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:
- ublast finds a hit to a characterized protein at above 40% identity and 80% coverage, and bits >= other bits+10.
- (Hits to curated proteins without experimental data as to their function are never considered high confidence.)
- HMMer finds a hit with 80% coverage of the model, and either other identity < 40 or other coverage < 0.75.
where "other" refers to the best ublast hit to a sequence that is not annotated as performing this step (and is not "ignored").
Otherwise, a candidate is "medium confidence" if either:
- ublast finds a hit at above 40% identity and 70% coverage (ignoring otherBits).
- ublast finds a hit at above 30% identity and 80% coverage, and bits >= other bits.
- HMMer finds a hit (regardless of coverage or other bits).
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:
- our ignorance of proteins' functions,
- omissions in the gene models,
- frame-shift errors in the genome sequence, or
- the organism lacks the pathway.
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