ManY (P69801) - Curation Notes

Gene Overview

ManY is the EIIC component of the mannose-specific phosphotransferase system (Man-PTS) in E. coli K12. Gene synonyms include pel (phage exclusion locus) and ptsP.

Key Literature Findings

Core Function: PTS EIIC Channel Component

• ManY (formerly II-PMan) is a very hydrophobic integral membrane protein (28 kDa) that forms the transmembrane channel together with ManZ (II-MMan) PMID:2951378
• The ManXYZ complex is the mannose-specific PTS permease consisting of three subunits encoded by the ptsLPM (manXYZ) operon PMID:2951378
• All three subunits are required for sugar transport and phosphorylation PMID:2951378
• ManY contains the specific substrate-binding site within its PTS EIIC type-4 domain [UniProt]

Structural Information

• Cryo-EM structure (3.52 A, PDB:6K1H) shows ManY-ManZ forms a homotrimer of heterodimers PMID:31209249
• Multiple transmembrane helices with complex topology including intramembrane helices [PMID:8774730, PMID:32710850]
• C-terminus is cytoplasmic, confirmed by GFP/PhoA fusions PMID:15919996

Substrate Specificity

• Primary substrate: mannose PMID:2951378
• Secondary substrates: glucose, fructose, N-acetylglucosamine [PMID:5545083, PMID:4153999, PMID:6252281]
• Glucose is primarily transported by PtsG; Man-PTS is a secondary glucose uptake system
• Fructose is primarily transported by FruAB; Man-PTS is a secondary fructose uptake system
• GlcNAc has two PTS systems: PtsM (Man-PTS) and another encoded near nagA,B PMID:6252281

Non-Transport Functions

• Bacteriophage lambda receptor: ManY and ManZ alone are sufficient for lambda DNA penetration PMID:2951378. Originally identified as "pel" mutations PMID:353494
• Chemoreceptor: PTS enzymes serve as chemoreceptors for sugars PMID:4604906

Annotation Review Summary

Accepted Core Annotations

• GO:0005886 (plasma membrane) - 4 annotations (IBA, IEA, 2x IDA): all accepted, well-supported
• GO:0009401 (PEP-dependent sugar PTS) - 3 annotations (IBA, IEA, IDA): all accepted, core BP
• GO:0015761 (mannose transmembrane transport) - 2 annotations (NAS, IDA): accepted, core BP
• GO:0022870 (protein-N(PI)-phosphohistidine-mannose PTS transporter activity) - IDA: accepted, core MF
• GO:0016020 (membrane) - 2 annotations (IEA, HDA): accepted, broader but correct

Non-Core Annotations (KEEP_AS_NON_CORE)

• GO:0015764 (N-acetylglucosamine transport) - secondary substrate
• GO:0098708 (D-glucose import across plasma membrane) - secondary substrate
• GO:1990539 (fructose import across plasma membrane) - 2 annotations, secondary substrate

New Annotations Suggested

• GO:1902495 (transmembrane transporter complex) - present in UniProt GO cross-refs but missing from GOA TSV

Open Questions

• Should phage lambda receptor and chemoreceptor functions have dedicated GO annotations?
• Are there additional sugar substrates transported by the Man-PTS?
• No deep research file was available for this gene; one could be generated for more comprehensive review.

Notes on Evidence

• Several key publications (PMID:353494, PMID:4604906, PMID:31209249, PMID:8774730) did not have cached full text in the publications directory
• PMID:5545083 (Kundig & Roseman 1971) had no abstract available in the cached file
• The review relied heavily on PMID:2951378 (Erni et al. 1987), which is the definitive characterization paper