As text, or see rules and steps
# Glutamine biosynthesis in GapMind is based on MetaCyc pathways # L-glutamine biosynthesis I from glutamine (metacyc:GLNSYN-PWY) # or glutaminyl-tRNA(Gln) biosynthesis via transamidation (metacyc:PWY-5921). # Both of these pathways require glutamate. The biosynthesis of glutamate # is not represented in GapMind, as glutamate can be formed by transamination of alpha-ketoglutarate, # an interemdiate in the TCA cycle. # A protein from Cupriavidus necator is reported to be a 3-hydroxylaminophenol mutase (see Swiss-Prot 3HAPM_CUPNJ), # involved in 3-nitrophenol degradation. That is the only glutamine synthetase-like protein # in the proteome of Cupriavidus necator (strain JMP 134 / LMG 1197) [see proteome UP000002697] # and is 96% identical to the essential protein RR42_RS12995 from Cupriavidus basilensis 4G11. # It is probably a glutamine synthetase. # metacyc:SYNPCC7942_2156-MONOMER is annotated with the same reaction, but was not originally given this EC number. # In SwissProt, uniprot:P81643 and uniprot:P85087 are annotated with this activity but they are very short, # so are ignored. # CKL_RS00630 (uniprot:A5N4G9) from Clostridium kluyveri is distantly related to # characterized glutamine synthetases, but the active site residues and transition state binding # residues are conserved (see alignment to 2whiA), so it is probably # the missing glnA. glnA glutamine synthetase EC:6.3.1.2 ignore_other:EC 5.4.4.3 curated:metacyc::SYNPCC7942_2156-MONOMER ignore:SwissProt::P81643 ignore:SwissProt::P85087 predicted:A5N4G9 predicted:A5N4G9 # Glutamyl-tRNA(Glu/Gln) is usually formed by a nondescriminating glutamyl-tRNA synthetase. # CCNA_01982 (uniprot:A0A0H3C8P5_CAUVN) from Caulobacter crescentus is the sole glutamyl-tRNA # synthetase, there is no glutaminyl-tRNA synthetase, and gatABC are present, # so we annotated it as non-discriminating. In contrast, as of March 2019, unirule # UR000075658 labeled it as EC:6.1.1.17 (the discriminating kind). # E. coli glutamine-tRNA ligase (uniprot:P00962) is misannotated in BRENDA as the non-discriminating ligase. # uniprot:Q8DLI5 is a non-discriminating glutamyl-tRNA synthetase # (PMID:16876193) but is not given this EC number # in SwissProt. gltX glutamyl-tRNA(Glx) synthetase EC:6.1.1.24 uniprot:A0A0H3C8P5_CAUVN ignore:BRENDA::P00962 curated:SwissProt::Q8DLI5 # The amidotransferase often acts on both glutamyl-tRNA(Gln) and aspartyl-tRNA(Asn) -- # do not try to distinguish. # Note there are no hits for some of these terms -- for some reason only gatB is annotated as a # aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit # Need to flag the metacyc entries separately because they have HTML tags in their descriptions gatA aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit A hmm:TIGR00132 term:aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit A term:glutamyl-tRNA(Gln) amidotransferase subunit A curated:metacyc::MONOMER-13955 ignore_other:EC 6.3.5.7 gatB aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit B hmm:TIGR00133 term:aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit B term:glutamyl-tRNA(Gln) amidotransferase subunit B curated:metacyc::MONOMER-13956 ignore_other:EC 6.3.5.7 gatC aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit C hmm:TIGR00135 term:aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit C term:glutamyl-tRNA(Gln) amidotransferase subunit C curated:metacyc::MONOMER-13957 ignore_other:EC 6.3.5.7 gatD glutamyl-tRNA(Gln) amidotransferase, subunit D hmm:TIGR02153 term:glutamyl-tRNA(Gln) amidotransferase subunit D ignore_other:EC 6.3.5.7 gatE glutamyl-tRNA(Gln) amidotransferase, subunit E hmm:TIGR00134 term:glutamyl-tRNA(Gln) amidotransferase subunit E ignore_other:EC 6.3.5.7 # Two types of glutamyl-tRNA amidotransferases are known, GatABC or GatDE. # GatABC are generally thought to act on both glutamyl-tRNA and aspartyl-tRNA, while # GatDE is thought to act only on glutamyl-tRNA. transamidation: gatA gatB gatC transamidation: gatD gatE to_glutamine: glnA # In the transamidation pathway, glutamate is ligated to tRNA, but free glutamine is still # required, because amidotransferase uses a glutaminase subunit to obtain ammonia. to_gln_tRNA: gltX glnA transamidation all: to_glutamine all: to_gln_tRNA
Each pathway is defined by a set of rules based on individual steps or genes. Candidates for each step are identified by using ublast (a fast alternative to protein BLAST) against a database of manually-curated proteins (most of which are experimentally characterized) or by using HMMer with enzyme models (usually from TIGRFam). Ublast hits may be split across two different proteins.
A candidate for a step is "high confidence" if either:
Otherwise, a candidate is "medium confidence" if either:
Other blast hits with at least 50% coverage are "low confidence."
Steps with no high- or medium-confidence candidates may be considered "gaps." For the typical bacterium that can make all 20 amino acids, there are 1-2 gaps in amino acid biosynthesis pathways. For diverse bacteria and archaea that can utilize a carbon source, there is a complete high-confidence catabolic pathway (including a transporter) just 38% of the time, and there is a complete medium-confidence pathway 63% of the time. Gaps may be due to:
GapMind relies on the predicted proteins in the genome and does not search the six-frame translation. In most cases, you can search the six-frame translation by clicking on links to Curated BLAST for each step definition (in the per-step page).
For more information, see:
If you notice any errors or omissions in the step descriptions, or any questionable results, please let us know
by Morgan Price, Arkin group, Lawrence Berkeley National Laboratory