Finding step msiK for D-cellobiose catabolism in Streptococcus oralis 7747
3 candidates for msiK: cellobiose ABC transporter, ATPase component
| Score | Gene | Description | Similar to | Id. | Cov. | Bits | Other hit | Other id. | Other bits |
|---|
| med | HK29_RS07485 | sn-glycerol-3-phosphate ABC transporter ATP-binding protein UgpC | MsiK protein, component of The cellobiose/cellotriose (and possibly higher cellooligosaccharides), CebEFGMsiK [MsiK functions to energize several ABC transporters including those for maltose/maltotriose and trehalose] (characterized) | 46% | 98% | 310.1 | MsmK aka SMU.882, component of The raffinose/stachyose transporter, MsmEFGK (MalK (3.A.1.1.27) can probably substitute for MsmK; Webb et al., 2008). This system may also transport melibiose, isomaltotriose and sucrose as well as isomaltosaccharides | 76% | 562.8 |
| lo | HK29_RS03610 | ABC transporter ATP-binding protein | MsiK protein, component of The cellobiose/cellotriose (and possibly higher cellooligosaccharides), CebEFGMsiK [MsiK functions to energize several ABC transporters including those for maltose/maltotriose and trehalose] (characterized) | 38% | 90% | 218.4 | Spermidine/putrescine import ATP-binding protein PotA, component of The spermidine/putrescine uptake porter, PotABCD | 99% | 754.2 |
| lo | HK29_RS00335 | ABC transporter ATP-binding protein | MsiK protein, component of The cellobiose/cellotriose (and possibly higher cellooligosaccharides), CebEFGMsiK [MsiK functions to energize several ABC transporters including those for maltose/maltotriose and trehalose] (characterized) | 38% | 59% | 160.2 | BilEA aka OpuBA protein, component of A proline/glycine betaine uptake system. Also reported to be a bile exclusion system that exports oxgall and other bile compounds, BilEA/EB or OpuBA/BB (required for normal virulence) | 56% | 258.8 |
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.
Definition of step msiK
- Curated sequence P96483: MsiK protein, component of The cellobiose/cellotriose (and possibly higher cellooligosaccharides), CebEFGMsiK [MsiK functions to energize several ABC transporters including those for maltose/maltotriose and trehalose]
- Ignore hits to Q9L0Q1 when looking for 'other' hits (Diacetylchitobiose uptake system ATP-binding protein MsiK; EC 7.5.2.-. ABC transporter ATP-binding protein, component of The N,N'-diacetylchitobiose uptake transporter, DasABC/MsiK (MsiK energizes several ABC transporters (see 3.A.1.1.23)))
- Comment: Ignore msiK from S. coelicolor (msiK is shared across ABC transporters)
Or cluster all characterized msiK proteins
This GapMind analysis is from Sep 24 2021. 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