Chemistry of Living Systems Semiannual Report, May 1 - Sep. 30, 1966

Biochemical mechanisms of heredity and gene expression, their adaptation to environmental extremes, and possible relationships to origin and development of lif

Chemistry of living systems Semiannual report, Apr. 1 - Sep. 30, 1967

Biochemical studies on nucleic acids, proteins, metabolisms, bacteriophages, and related topic

Present Status of the Amino Acid Code

Protein composition studies and present status of amino acid cod

Repetitions in the polypeptide sequence of cytochromes

Protein evolution from peptides, gene duplications and deletions in polypeptides and cytochrome

Specific Nature of Hydrolysis of Insulin and Tobacco Mosaic Virus Protein by Thermolysin

Oxidized bovine insulin and tobacco mosaic virus protein used to determine hydrolysis specificity of thermolysi

Molecules and Evolution

Biochemical basis of evolution - evolution and DNA, genetic code, microbiology and heredity, mutations, and evolution and hemoglobin

Chemistry of living systems Semiannual report, 1 Oct. 1966 - 31 Mar. 1967

Reconstitution of ribosomes, evolution of enzyme systems in pseudomonas, molecular mechanism for T4 bacteriophage, and other studies related to evolution and chemistry of living system

Specific recognition of a multiply phosphorylated motif in the DNA repair scaffold XRCC1 by the FHA domain of human PNK.

Short-patch repair of DNA single-strand breaks and gaps (SSB) is coordinated by XRCC1, a scaffold protein that recruits the DNA polymerase and DNA ligase required for filling and sealing the damaged strand. XRCC1 can also recruit end-processing enzymes, such as PNK (polynucleotide kinase 3'-phosphatase), Aprataxin and APLF (aprataxin/PNK-like factor), which ensure the availability of a free 3'-hydroxyl on one side of the gap, and a 5'-phosphate group on the other, for the polymerase and ligase reactions respectively. PNK binds to a phosphorylated segment of XRCC1 (between its two C-terminal BRCT domains) via its Forkhead-associated (FHA) domain. We show here, contrary to previous studies, that the FHA domain of PNK binds specifically, and with high affinity to a multiply phosphorylated motif in XRCC1 containing a pSer-pThr dipeptide, and forms a 2:1 PNK:XRCC1 complex. The high-resolution crystal structure of a PNK-FHA-XRCC1 phosphopeptide complex reveals the basis for this unusual bis-phosphopeptide recognition, which is probably a common feature of the known XRCC1-associating end-processing enzymes