HMDB

HMDB catalogs curated hydrocarbon monooxygenase genes to enable identification of microbial hydrocarbon degradation potential in genomic and metagenomic datasets.

Key Features:

• Curated Gene Database: HMDB contains 38 genes that encode 11 distinct monooxygenases responsible for the hydroxylation of eight different hydrocarbons.
• Background Noise Reduction: HMDB incorporates 10,095 homologous gene sequences from enzymes that utilize non-hydrocarbon substrates to minimize false positives.
• Comprehensive Validation: HMDB was validated against 264,402 prokaryote genomes from RefSeq and 51 metagenomes from SRA, demonstrating high sensitivity and a low false positive rate.
• Search Methods: HMDB recommends using the classic BLAST method with a best-hit strategy for querying the database.

Scientific Applications:

• Aerobic hydrocarbon degradation profiling: Identification and analysis of monooxygenase-mediated hydrocarbon degradation pathways in environmental microorganisms under aerobic conditions.
• Metagenomic screening and gene identification: Rapid detection and characterization of monooxygenase genes in large-scale metagenomic datasets.
• Bioremediation and carbon cycle research: Supporting studies of microbial contributions to oil pollution remediation and the global carbon cycle through targeted gene-level evidence.

Methodology:

Development involved systematic gene curation, inclusion of 10,095 homologous genes as background noise to distinguish true hydrocarbon monooxygenases from similar non-hydrocarbon enzymes, and validation by screening 264,402 RefSeq prokaryote genomes and 51 SRA metagenomes; classic BLAST with a best-hit strategy is recommended for queries.