Taxonomic distribution of proteins containing KU domains

The KU domain within your query sequence starts at position 154 and ends at position 207, and its E-value is 1.33e-19.

Inter-alpha-trypsin inhibitor: emergence of a family within the Kunitz-type protease inhibitor superfamily.

Salier JP
Trends Biochem Sci. 1990; 15: 435-9

Plasma inter-alpha-trypsin inhibitor (I alpha TI) is a major representative of the superfamily of Kunitz-type protease inhibitors in mammals. Formerly, I alpha TI was considered to be a single polypeptide, but recent molecular genetic studies have demonstrated an unexpected multipolypeptide chain structure. The newly discovered genes and gene products form the basis of a new family of I alpha TI-related protease inhibitors.

A new A4 amyloid mRNA contains a domain homologous to serine proteinase inhibitors.

Ponte P, Gonzalez-DeWhitt P, Schilling J, Miller J, Hsu D, Greenberg B, Davis K, Wallace W, Lieberburg I, Fuller F
Nature. 1988; 331: 525-7

The amyloid proteins isolated from neuritic plaques and the cerebrovasculature of Alzheimer's disease are self-aggregating moieties termed A4 protein and beta-protein, respectively. A putative A4 amyloid precursor (herein termed A4(695] has been characterized by analysis of a human brain complementary DNA. We report here the sequence of a closely related amyloid cDNA, A4(751), distinguished from A4(695) by the presence of a 168 base-pair (bp) sequence which adds 57 amino acids to, and removes one residue from, the predicted A4(695) protein. The peptide predicted from this insert is very similar to the Kunitz family of serine proteinase inhibitors. The two A4-specific messenger RNAs are differentially expressed: in a limited survey, A4(751) mRNA appears to be ubiquitous, whereas A4(695) mRNA has a restricted pattern of expression which includes cells from neuronal tissue. These data may have significant implications for understanding amyloid deposition in Alzheimer's disease.

Protease inhibitor domain encoded by an amyloid protein precursor mRNA associated with Alzheimer's disease.

Tanzi RE, McClatchey AI, Lamperti ED, Villa-Komaroff L, Gusella JF, Neve RL
Nature. 1988; 331: 528-30

Amyloid B-protein/amyloid A4 is a peptide present in the neuritic plaques, neurofibrillary tangles and cerebrovascular deposits in patients with Alzheimer's disease and Down's syndrome (trisomy 21) and may be involved in the pathogenesis of Alzheimer's disease. Recent molecular genetic studies have indicated that amyloid protein is encoded as part of a larger protein by a gene on human chromosome 21 (refs 6-9). The amyloid protein precursor (APP) gene is expressed in brain and in several peripheral tissues, but the specific biochemical events leading to deposition of amyloid are not known. We have now screened complementary DNA libraries constructed from peripheral tissues to determine whether the messenger RNA encoding APP in these tissues is identical to that expressed in brain, and we identify a second APP mRNA that encodes an additional internal domain with a sequence characteristic of a Kunitz-type serine protease inhibitor. The alternative APP mRNA is present in both brain and peripheral tissues of normal individuals and those with Alzheimer's disease, but its pattern of expression differs from that of the previously reported APP mRNA.

Protein inhibitors of proteinases.

LaskowskiMJ r, Kato I
Annu Rev Biochem. 1980; 49: 593-626