KofamKOALA

KofamKOALA assigns KEGG Orthologs (KOs) to protein sequences using KOfam profile hidden Markov models (HMMs) and pre-computed adaptive score thresholds to enable accurate functional annotation and pathway mapping.


Key Features:

  • Profile HMM-Based Assignment: Uses KOfam profile HMMs to compare protein sequences against KO models, typically using HMMER/HMMSEARCH.
  • Adaptive Score Thresholding: Applies KO-dependent pre-computed adaptive score thresholds to determine assignments and marks assignments exceeding thresholds with an asterisk '*' to indicate high confidence.
  • Efficiency and Accuracy: Optimized for computational speed while achieving accuracy comparable to top-performing KO assignment methods.
  • Integration with KEGG Resources: Assigns K numbers that enable linking genes to KEGG pathway maps and support molecular network reconstruction.

Scientific Applications:

  • Functional Annotation: Assigns KOs to proteins to infer gene functions based on orthology.
  • Pathway Mapping: Connects assigned K numbers to KEGG pathway maps for analysis of biological processes.
  • Network Reconstruction: Facilitates construction of molecular networks by linking genes and enzymes via KEGG identifiers.

Methodology:

Performs homology searches of protein sequences against KOfam profile HMMs (e.g., using HMMER/HMMSEARCH), then applies KO-dependent pre-computed adaptive score thresholds to assign K numbers and flag high-confidence annotations.

Topics

Details

Tool Type:
web application
Added:
1/14/2020
Last Updated:
11/24/2024

Operations

Publications

Aramaki T, Blanc-Mathieu R, Endo H, Ohkubo K, Kanehisa M, Goto S, Ogata H. KofamKOALA: KEGG Ortholog assignment based on profile HMM and adaptive score threshold. Bioinformatics. 2019;36(7):2251-2252. doi:10.1093/bioinformatics/btz859. PMID:31742321. PMCID:PMC7141845.

PMID: 31742321
PMCID: PMC7141845
Funding: - JSPS/MEXT/KAKENHI: 16H06429, 16H06437, 16K21723, 18H02279, 26430184 - Collaborative Research Program of the Institute for Chemical Research, Kyoto University: 2018-30