Protein: Abasic site processing protein HMCES (Q6IND6)
Organism: Xenopus laevis (African clawed frog)
Function: Sensor of abasic sites in single-stranded DNA (ssDNA) required to preserve genome integrity by promoting error-free repair of abasic sites (By similarity). Acts as an enzyme that recognizes and binds abasic sites in ssDNA at replication forks and chemically modifies the lesion by forming a covalent cross-link with DNA: forms a stable thiazolidine linkage between a ring-opened abasic site and the alpha-amino and sulfhydryl substituents of its N-terminal catalytic cysteine residue (By similarity). The hmces DNA-protein cross-link is then either reversed or degraded. Hmces is able to catalyze the reversal of its thiazolidine cross-link and cycle between a cross-link and a non-cross- linked state depending on DNA context: mediates self-reversal of the thiazolidine cross-link in double stranded DNA, allowing apex1 to initiate downstream repair of abasic sites. The hmces DNA-protein cross-link can also be degraded by the sprtn metalloprotease following unfolding by the brip1/fancj helicase . Promotes error-free repair of abasic sites by protecting abasic sites from translesion synthesis (TLS) polymerases and endonucleases that are error-prone and would generate mutations and double-strand breaks (By similarity). Acts as a protease: mediates autocatalytic processing of its N-terminal methionine in order to expose the catalytic cysteine (By similarity). The HMCES DNA-protein cross-link is then either reversed or degraded (By similarity). According to a model, the HMCES DNA-protein cross-link (By similarity)
Subcellular location: Chromosome. Note=Recruited to chromatin following DNA damage. Localizes to replication forks
InterPro domains:
- IPR003738: SOS response associated peptidase (SRAP) (family) [1-324]
- IPR036590: SOS response associated peptidase-like (homologous_superfamily) [1-268]
Sequence:
MCGRTACTLAPDDVSKACSYQDKQGRQKCPKWRDGDTDKYQPSYNKSPQSNNPVLLSLKHFQKDADSSERVLAAMRWGLIPSWFNELDPSKMQYKTNNCRSDTITEKALYKAPLFKGRRCVVLADGFYEWKRQDGEKQPYYIYFPQIKSEKFPEEQDMMDWNGQRLLTMAGLFDCWEPPSGGEPLYSYTVITVDSSKTMNCIHDRMPAILDGDEAIRKWLDFGEVSTQDALKLIHPIENITYHPVSTVVNNSRNNSTECIAAVILTQKKGPALSASSKKMLEWLQNKSPKKEESRSIIQSPKLSQFGAPPKKTSAGLMQQWLKKEDGEPSPKRAKK
Predicted GO terms:
Molecular Function (MF): GO:0003674 (molecular function), GO:0005488 (binding), GO:0097159 (organic cyclic compound binding), GO:1901363 (heterocyclic compound binding), GO:0003676 (nucleic acid binding), GO:0003677 (DNA binding), GO:0003697 (single-stranded DNA binding)
Biological Process (BP): GO:0008150 (biological process), GO:0008152 (metabolic process), GO:0009987 (cellular process), GO:0050896 (response to stimulus), GO:0051716 (cellular response to stimulus), GO:0006950 (response to stress), GO:0071704 (organic substance metabolic process), GO:0044238 (primary metabolic process), GO:0006807 (nitrogen compound metabolic process), GO:1901564 (organonitrogen compound metabolic process), GO:0019538 (protein metabolic process), GO:0043170 (macromolecule metabolic process), GO:0033554 (cellular response to stress), GO:0036211 (protein modification process), GO:0043412 (macromolecule modification), GO:0006974 (cellular response to DNA damage stimulus)
Cellular Component (CC): GO:0005575 (cellular component), GO:0110165 (cellular anatomical entity), GO:0005622 (intracellular anatomical structure), GO:0043226 (organelle), GO:0043229 (intracellular organelle), GO:0043227 (membrane-bounded organelle), GO:0043231 (intracellular membrane-bounded organelle), GO:0005634 (nucleus)