An identity threshold must be specified using the -id option.
A database file must be specified using the -db option.
The -strand option is required for nucleotide databases.
Nucleotide, protein and translated searches are supported.
See also:
Standard output file options
Accept options
Weak hits
Termination options
Multithreading
Alignment parameters
Example
usearch -search_global query.fasta -db db.fasta -id 0.9 -alnout results.aln