HHBLITS_OMP(1)

๐ŸŒธ NAME ๐ŸŒธ

hhblits_omp โ€” fast homology detection method to iteratively search a HMM database ๐Ÿ’ซ

(yes bestie, this is the HHBLITS_OMP(1) page โ€” User Commands energy, we're in the right place ๐Ÿซถ)


โœจ SYNOPSIS โœจ

hhblits -i query [options]

๐Ÿ’– DESCRIPTION ๐Ÿ’–

HHblits 3.3.0: HMM-HMM-based lightning-fast iterative sequence search ๐Ÿ”ฅ

okay so here's the vibe: HHblits is a sensitive, general-purpose, iterative sequence search tool that represents both query and database sequences by HMMs. You can search HHblits databases starting with a single query sequence, a multiple sequence alignment (MSA), or an HMM. HHblits prints out a ranked list of database HMMs/MSAs and โ€” plot twist โ€” it can also generate an MSA by merging the significant database HMMs/MSAs onto the query MSA. it's giving "search engine but make it structural" ๐Ÿ’…


Steinegger M, Meier M, Mirdita M, V??hringer H, Haunsberger S J, and S??ding J (2019) HH-suite3 for fast remote homology detection and deep protein annotation. BMC Bioinformatics, doi:10.1186/s12859-019-3019-7

(c) The HH-suite development team


  • -i <file> โ€” input/query: single sequence or multiple sequence alignment (MSA) in a3m, a2m, or FASTA format, or HMM in hhm format ๐ŸŒˆ
heads up: <file> may be 'stdin' or 'stdout' throughout. iconic behaviour tbh ๐ŸŽ€

๐Ÿ‘‘ OPTIONS ๐Ÿ‘‘

  • -d <name> โ€” database name (e.g. uniprot20_29Feb2012). Multiple databases may be specified with '-d <db1> -d <db2> ...' ๐Ÿ—‚๏ธ
  • -n โ€” [1,8] number of iterations (default=2)
  • -e โ€” [0,1] E-value cutoff for inclusion in result alignment (def=0.001)

๐ŸŽ€ Input alignment format: ๐ŸŽ€

  • -M a2m โ€” use A2M/A3M (default): upper case = Match; lower case = Insert; ' -' = Delete; '.' = gaps aligned to inserts (may be omitted) ๐Ÿงฌ
  • -M first โ€” use FASTA: columns with residue in 1st sequence are match states
  • -M [0,100] โ€” use FASTA: columns with fewer than X% gaps are match states
  • -tags / -notags โ€” do NOT / do neutralize His-, C-myc-, FLAG-tags, and trypsin recognition sequence to background distribution (def=-notags) ๐Ÿ™ˆ

๐Ÿ“ค Output options: ๐Ÿ“ค

  • -o <file> โ€” write results in standard format to file (default=<infile.hhr>)
  • -oa3m <file> โ€” write result MSA with significant matches in a3m format
  • -opsi <file> โ€” write result MSA of significant matches in PSI-BLAST format
  • -ohhm <file> โ€” write HHM file for result MSA of significant matches
  • -oalis <name> โ€” write MSAs in A2M format after each iteration
  • -blasttab <name> โ€” write result in tabular BLAST format (compatible to -m 8 or -outfmt 6 output) ๐Ÿ“Š
1      2      3           4         5        6      8    9      10   11      12

'query target #match/tLen #mismatch #gapOpen qstart qend tstart tend eval score'

  • -add_cons โ€” generate consensus sequence as master sequence of query MSA (default=don't)
  • -hide_cons โ€” don't show consensus sequence in alignments (default=show)
  • -hide_pred โ€” don't show predicted 2ndary structure in alignments (default=show)
  • -hide_dssp โ€” don't show DSSP 2ndary structure in alignments (default=show)
  • -show_ssconf โ€” show confidences for predicted 2ndary structure in alignments โœจ
  • -Ofas <file> โ€” write pairwise alignments in FASTA xor A2M (-Oa2m) xor A3M (-Oa3m) format
  • -seq <int> โ€” max. number of query/template sequences displayed (default=1)
  • -aliw <int> โ€” number of columns per line in alignment list (default=80)
  • -p [0,100] โ€” minimum probability in summary and alignment list (default=20)
  • -E [0,inf[ โ€” maximum E-value in summary and alignment list (default=1E+06)
  • -Z <int> โ€” maximum number of lines in summary hit list (default=500)
  • -z <int> โ€” minimum number of lines in summary hit list (default=10)
  • -B <int> โ€” maximum number of alignments in alignment list (default=500)
  • -b <int> โ€” minimum number of alignments in alignment list (default=10)

๐Ÿ•ต๏ธ Prefilter options ๐Ÿ•ต๏ธ

  • -noprefilt โ€” disable all filter steps
  • -noaddfilter โ€” disable all filter steps (except for fast prefiltering)
  • -maxfilt โ€” max number of hits allowed to pass 2nd prefilter (default=20000)
  • -min_prefilter_hits โ€” min number of hits to pass prefilter (default=100)
  • -prepre_smax_thresh โ€” min score threshold of ungapped prefilter (default=10)
  • -pre_evalue_thresh โ€” max E-value threshold of Smith-Waterman prefilter score (default=1000.0)
  • -pre_bitfactor โ€” prefilter scores are in units of 1 bit / pre_bitfactor (default=4)
  • -pre_gap_open โ€” gap open penalty in prefilter Smith-Waterman alignment (default=20)
  • -pre_gap_extend โ€” gap extend penalty in prefilter Smith-Waterman alignment (default=4)
  • -pre_score_offset โ€” offset on sequence profile scores in prefilter S-W alignment (default=50)

๐Ÿงผ Filter options applied to query MSA, database MSAs, and result MSA ๐Ÿงผ

  • -all โ€” show all sequences in result MSA; do not filter result MSA
  • -interim_filter NONE|FULL โ€” filter sequences of query MSA during merging to avoid early stop (default: FULL)
    • NONE: disables the intermediate filter
    • FULL: if an early stop occurs compare filter seqs in an all vs. all comparison
  • -id [0,100] โ€” maximum pairwise sequence identity (def=90)
  • -diff [0,inf[ โ€” filter MSAs by selecting most diverse set of sequences, keeping at least this many seqs in each MSA block of length 50. Zero and non-numerical values turn off the filtering. (def=1000)
  • -cov [0,100] โ€” minimum coverage with master sequence (%) (def=0)
  • -qid [0,100] โ€” minimum sequence identity with master sequence (%) (def=0)
  • -qsc [0,100] โ€” minimum score per column with master sequence (default=-20.0)
  • -neff [1,inf] โ€” target diversity of multiple sequence alignment (default=off)
  • -mark โ€” do not filter out sequences marked by ">@" in their name line

๐Ÿ’… HMM-HMM alignment options: ๐Ÿ’…

  • -norealign โ€” do NOT realign displayed hits with MAC algorithm (def=realign)
  • -realign_old_hits โ€” realign hits from previous iterations
  • -mact [0,1[ โ€” posterior prob threshold for MAC realignment controlling greediness at alignment ends: 0:global >0.1:local (default=0.35)
  • -glob / -loc โ€” use global/local alignment mode for searching/ranking (def=local)
  • -realign โ€” realign displayed hits with max. accuracy (MAC) algorithm
  • -realign_max <int> โ€” realign max. <int> hits (default=500)
  • -ovlp <int> โ€” banded alignment: forbid <ovlp> largest diagonals |i-j| of DP matrix (def=0)
  • -alt <int> โ€” show up to this many alternative alignments with raw score > smin (def=4)
  • -premerge <int> โ€” merge <int> hits to query MSA before aligning remaining hits (def=3)
  • -smin <float> โ€” minimum raw score for alternative alignments (def=20.0)
  • -shift [-1,1] โ€” profile-profile score offset (def=-0.03)
  • -corr [0,1] โ€” weight of term for pair correlations (def=0.10)
  • -sc <int> โ€” amino acid score (tja: template HMM at column j) (def=1)
    • 0 = log2 Sum(tja*qia/pa) (pa: aa background frequencies)
    • 1 = log2 Sum(tja*qia/pqa) (pqa = 1/2*(pa+ta) )
    • 2 = log2 Sum(tja*qia/ta) (ta: av. aa freqs in template)
    • 3 = log2 Sum(tja*qia/qa) (qa: av. aa freqs in query)
    • 5 โ€” local amino acid composition correction
  • -ssm {0,..,4}
    • 0: no ss scoring
    • 1,2: ss scoring after or during alignment [default=2]
    • 3,4: ss scoring after or during alignment, predicted vs. predicted
  • -ssw [0,1] โ€” weight of ss score (def=0.11)
  • -ssa [0,1] โ€” ss confusion matrix = (1-ssa)*I + ssa*psipred-confusion-matrix [def=1.00)
  • -wg โ€” use global sequence weighting for realignment!

๐Ÿงš Gap cost options: ๐Ÿงš

  • -gapb [0,inf[ โ€” Transition pseudocount admixture (def=1.00)
  • -gapd [0,inf[ โ€” Transition pseudocount admixture for open gap (default=0.15)
  • -gape [0,1.5] โ€” Transition pseudocount admixture for extend gap (def=1.00)
  • -gapf ]0,inf] โ€” factor to increase/reduce gap open penalty for deletes (def=0.60)
  • -gapg ]0,inf] โ€” factor to increase/reduce gap open penalty for inserts (def=0.60)
  • -gaph ]0,inf] โ€” factor to increase/reduce gap extend penalty for deletes (def=0.60)
  • -gapi ]0,inf] โ€” factor to increase/reduce gap extend penalty for inserts (def=0.60)
  • -egq [0,inf[ โ€” penalty (bits) for end gaps aligned to query residues (def=0.00)
  • -egt [0,inf[ โ€” penalty (bits) for end gaps aligned to template residues (def=0.00)

๐Ÿ”ฎ Pseudocount (pc) options: ๐Ÿ”ฎ

Context specific hhm pseudocounts:

  • -pc_hhm_contxt_mode {0,..,3} โ€” position dependence of pc admixture 'tau' (pc mode, default=2)
    • 0: no pseudo counts: tau = 0
    • 1: constant tau = a
    • 2: diversity-dependent: tau = a/(1+((Neff[i]-1)/b)^c)
    • 3: CSBlast admixture: tau = a(1+b)/(Neff[i]+b) (Neff[i]: number of effective seqs in local MSA around column i)
  • -pc_hhm_contxt_a [0,1] โ€” overall pseudocount admixture (def=0.9)
  • -pc_hhm_contxt_b [1,inf[ โ€” Neff threshold value for mode 2 (def=4.0)
  • -pc_hhm_contxt_c [0,3] โ€” extinction exponent c for mode 2 (def=1.0)

Context independent hhm pseudocounts (used for templates; used for query if contxt file is not available):

  • -pc_hhm_nocontxt_mode {0,..,3} โ€” position dependence of pc admixture 'tau' (pc mode, default=2)
    • 0: no pseudo counts: tau = 0
    • 1: constant tau = a
    • 2: diversity-dependent: tau = a/(1+((Neff[i]-1)/b)^c) (Neff[i]: number of effective seqs in local MSA around column i)
  • -pc_hhm_nocontxt_a [0,1] โ€” overall pseudocount admixture (def=1.0)
  • -pc_hhm_nocontxt_b [1,inf[ โ€” Neff threshold value for mode 2 (def=1.5)
  • -pc_hhm_nocontxt_c [0,3] โ€” extinction exponent c for mode 2 (def=1.0)

Context specific prefilter pseudocounts:

  • -pc_prefilter_contxt_mode {0,..,3} โ€” position dependence of pc admixture 'tau' (pc mode, default=3)
    • 0: no pseudo counts: tau = 0
    • 1: constant tau = a
    • 2: diversity-dependent: tau = a/(1+((Neff[i]-1)/b)^c)
    • 3: CSBlast admixture: tau = a(1+b)/(Neff[i]+b) (Neff[i]: number of effective seqs in local MSA around column i)
  • -pc_prefilter_contxt_a [0,1] โ€” overall pseudocount admixture (def=0.8)
  • -pc_prefilter_contxt_b [1,inf[ โ€” Neff threshold value for mode 2 (def=2.0)
  • -pc_prefilter_contxt_c [0,3] โ€” extinction exponent c for mode 2 (def=1.0)

โœจ Context independent prefilter pseudocounts (used if context file is not available) โœจ

so this is the fallback squad ๐Ÿซถ these settings only show up when there's no context file to work with. no context file? we still eat. ๐Ÿ’…

  • -pc_prefilter_nocontxt_mode {0,..,3} โ€” how position-dependent the pc admixture tau is (pc mode, default=2)
    • 0: no pseudo counts: tau = 0
    • 1: constant tau = a
    • 2: diversity-dependent: tau = a/(1+((Neff[i]-1)/b)^c) (where Neff[i] is the number of effective seqs in the local MSA around column i)
  • -pc_prefilter_nocontxt_a โ€” [0,1] overall pseudocount admixture (def=1.0)
  • -pc_prefilter_nocontxt_b โ€” [1,inf[ Neff threshold value for mode 2 (def=1.5)
  • -pc_prefilter_nocontxt_c โ€” [0,3] extinction exponent c for mode 2 (def=1.0)

๐Ÿ’œ Context-specific pseudo-counts ๐Ÿ’œ

now we're in the โœจfancyโœจ section, bestie. this is where the pseudocounts actually know what's going on around them.

  • -nocontxt โ€” use substitution-matrix instead of context-specific pseudocounts
  • -contxt <file> โ€” context file for computing context-specific pseudocounts (default=)
  • -csw โ€” [0,inf] weight of central position in cs pseudocount mode (def=1.6)
  • -csb โ€” [0,1] weight decay parameter for positions in cs pc mode (def=0.9)

๐ŸŽ€ Other options ๐ŸŽ€

the grab bag. the little extras. the main character energy side quests. ๐Ÿ‘‘

  • -v <int> โ€” verbose mode: 0:no screen output, 1:only warings, 2: verbose (def=2) โ€” yes it really says "warings", and honestly? iconic. we respect the typo. ๐Ÿ’€
  • -neffmax ]1,20] โ€” skip further search iterations when the diversity Neff of the query MSA becomes larger than neffmax (default=20.0)
  • -cpu <int> โ€” number of CPUs to use (for shared memory SMPs) (default=2)
  • -scores <file> โ€” write scores for all pairwise comparisons to file
  • -filter_matrices โ€” filter matrices for similarity, to output at most 100 matrices
  • -atab <file> โ€” write all alignments in tabular layout to file
  • -maxseq <int> โ€” max number of input rows (def=65535)
  • -maxres <int> โ€” max number of HMM columns (def=20001)
  • -maxmem [1,inf[ โ€” limit memory for realignment (in GB) (def=3.0)

โœจ EXAMPLES โœจ

okay bestie, here's the part you actually came for. copy, paste, slay. ๐ŸŒˆ

hhblits -i query.fas -o query.hhr -d ./uniclust30
hhblits -i query.fas -o query.hhr -oa3m query.a3m -n 1 -d ./uniclust30

and when you need the databases themselves, grab them from <http://wwwuser.gwdg.de/~compbiol/data/hhsuite/databases/hhsuite_dbs/> ๐Ÿฆ‹

go forth, run your searches, and let the MSA cook. no cap. ๐Ÿ”ฅ

that's the whole page, babe โ€” hhblits_omp version 3.3.0+ds, dated August 2023, filed under HHBLITS_OMP(1). thanks for reading all the way to the end, you're literally the bestie of all time. ๐ŸŽ€๐Ÿ’–

๐Ÿ“ฆ where this page comes from