Protein: Homocysteine/cysteine synthase (Q12198)
Organism: Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast)
Function: Plays a role in inorganic sulfur assimilation during sulfur- limited conditions; catalyzes the conversion of O-acetyl-L-homoserine (OAH) into homocysteine in the methionine biosynthesis pathway . Also catalyzes the conversion of O- acetylserine (OAS) into cysteine, the last step in the cysteine biosynthesis pathway. However, it seems that in S.cerevisiae cysteine biosynthesis occurs exclusively through the cystathionine pathway and not via direct incorporation of sulfur into OAS (By similarity). It therefore has no metabolic role in cysteine biosynthesis and may only have a regulatory role controlling OAS levels (By similarity)
Subcellular location: Cytoplasm
InterPro domains:
- IPR051750: Trans-sulfuration enzymes (family) [166-569]
- IPR015421: Pyridoxal phosphate-dependent transferase, major domain (homologous_superfamily) [182-421]
- IPR015424: Pyridoxal phosphate-dependent transferase (homologous_superfamily) [207-565]
- IPR015422: Pyridoxal phosphate-dependent transferase, small domain (homologous_superfamily) [432-574]
- IPR000277: Cys/Met metabolism, pyridoxal phosphate-dependent enzyme (family) [303-564]
Sequence:
MTEIEFGQPLPSNLDYAVSFGIPTWDSAIGYAEKVPEVIGKMATGYPRYFPQPPVQRLCAYFVKKFGRGSENCRPFPSVNLGLKCFEYVKSVSGPESKAHLEVETVTIKNRGAKTSKEPAELVLTIAAVLASEEEFETVKEYWKLRGECVSSRLALSVNQLLDCANHGSEQVLRELEAGVFAAKKGEEKAKNLIKGRIVENRFRPFGLEKKTPNWEGLNLNPNEDVYLVSSGMSAISTARNLLTFWEEKKNSGDSLNKTTSDQKKKPLLCDTVGIFGFPFKDTQVIMTKFGKCKFFGFGNSRDVVELQKFLETSKQRILAVFVETPSNPLLNMPDLKKLRSLADQYGFFIVIDDTIGGLNVDILPYADIVSTSLTKLFNGASNVMGGSVVLNPKSSLYPYAREYFRSANFEDLLWCEDAIVLERNSRDFEDRTLRANANTGILLNDLLLPEEGKICKKIYYPTVTSKETFENYESVRNERGGYGCLFSVAFFNEGDAKAFYDSLKVFKGPSNGTNFTLACPYVHLAHHSELEEVSKFGADPNIIRVSVGLEDIQWLLKVFSSALDVVKSRGSKHS
Predicted GO terms:
Molecular Function (MF): GO:0003674 (molecular function), GO:0003824 (catalytic activity), GO:0016740 (transferase activity), GO:0016765 (transferase activity, transferring alkyl or aryl (other than methyl) groups)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0009058 (biosynthetic process), GO:0044237 (cellular metabolic process), GO:0071704 (organic substance metabolic process), GO:0044281 (small molecule metabolic process), GO:0044238 (primary metabolic process), GO:0006807 (nitrogen compound metabolic process), GO:0044249 (cellular biosynthetic process), GO:0006520 (amino acid metabolic process), GO:1901576 (organic substance biosynthetic process), GO:1901564 (organonitrogen compound metabolic process), GO:0044283 (small molecule biosynthetic process), GO:0006790 (sulfur compound metabolic process), GO:0006082 (organic acid metabolic process), GO:1901566 (organonitrogen compound biosynthetic process), GO:0000096 (sulfur amino acid metabolic process), GO:0044272 (sulfur compound biosynthetic process), GO:0008652 (amino acid biosynthetic process), GO:0016053 (organic acid biosynthetic process), GO:0043436 (oxoacid metabolic process), GO:1901605 (alpha-amino acid metabolic process), GO:0019752 (carboxylic acid metabolic process), GO:0000097 (sulfur amino acid biosynthetic process), GO:0046394 (carboxylic acid biosynthetic process), GO:1901607 (alpha-amino acid biosynthetic process), GO:0009066 (aspartate family amino acid metabolic process), GO:0006555 (methionine metabolic process), GO:0009067 (aspartate family amino acid biosynthetic process), GO:0009086 (methionine biosynthetic process)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0005737 (cytoplasm), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0043231 (intracellular membrane-bounded organelle), GO:0005634 (nucleus)