Finding step nupC for 2'-deoxyinosine catabolism in Escherichia coli BW25113
3 candidates for nupC: deoxyinosine:H+ symporter NupC
| Score | Gene | Description | Similar to | Id. | Cov. | Bits | Other hit | Other id. | Other bits |
|---|
| hi | b2393 | nucleoside (except guanosine) transporter (NCBI) | Nucleoside permease NupC; Nucleoside-transport system protein NupC (characterized) | 100% | 100% | 754.2 | Nucleoside permease NupC | 60% | 439.1 |
| hi | b2164 | predicted nucleoside transporter (NCBI) | Concentrative nucleoside transporter, CNT, of 418 aas and 12 TMSs. A repeat-swapped model of VcCNT predicts that nucleoside transport occurs via a mechanism involving an elevator-like substrate binding domain movement across the membrane (characterized) | 51% | 100% | 421.4 | Broadly selective nucleoside:Na+ cotransporter, hfCNT (transports uridine, thymidine, inosine, 3'-azido-3'deoxythymidine, 2'3'dideoxycytidine, and 2'3'dideoxyinosine) (Na+/uridine = 2) | 35% | 268.1 |
| hi | b2161 | predicted nucleoside transporter (NCBI) | Concentrative nucleoside transporter, CNT, of 418 aas and 12 TMSs. A repeat-swapped model of VcCNT predicts that nucleoside transport occurs via a mechanism involving an elevator-like substrate binding domain movement across the membrane (characterized) | 51% | 100% | 419.9 | Broadly selective nucleoside:Na+ cotransporter, hfCNT (transports uridine, thymidine, inosine, 3'-azido-3'deoxythymidine, 2'3'dideoxycytidine, and 2'3'dideoxyinosine) (Na+/uridine = 2) | 35% | 268.1 |
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 nupC
- Curated sequence O25792: Nucleoside permease NupC
- Curated sequence P0AFF2: Nucleoside permease NupC; Nucleoside-transport system protein NupC. Pyrimidine nucleoside:H+ symporter, NupC (Craig et al. 1994; Patching et al. 2005). Wild-type NupC had an apparent affinity for uridine of 22.2 +/- 3.7 muM and an apparent binding affinity of 1.8-2.6 mM, and various mutants with alterred properties were isolated and characterized (Sun et al. 2017). ADP-glucose is also a substrate of this system. nucleoside:H+ symporter NupC. nucleoside:H+ symporter NupC
- Curated sequence P42312: Purine nucleoside transport protein NupG. The purine nucleoside uptake transporter NupG (YxjA)
- Curated sequence Q9KPL5: Concentrative nucleoside transporter, CNT, of 418 aas and 12 TMSs. A repeat-swapped model of VcCNT predicts that nucleoside transport occurs via a mechanism involving an elevator-like substrate binding domain movement across the membrane
- Ignore hits to P33021 when looking for 'other' hits (Putative nucleoside permease NupX. Nucleoside permease NupX. putative nucleoside transporter)
- Comment: These proteins are reported to transport inosine, and likely transport deoxyinosine as well. The specificity of E. coli nupX (P33021, also known as yeiJ) seems to be unknown.
Or cluster all characterized nupC 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