Open AccessEXAFS analysis of the zinc‐binding domain of boar spermatidal transition protein 2
Author(s) -
Kawai Takeshi,
Konishi Takehisa,
Fujikawa Takashi,
Sekine Atushi,
Imai Lica F.,
Akama Kuniko
Publication year - 2001
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s0909049500014527
Subject(s) - zinc , extended x ray absorption fine structure , chemistry , crystallography , boar , sulfur , absorption spectroscopy , organic chemistry , biology , physics , botany , quantum mechanics , sperm
Boar Spermatidal Transition Protein 2 (TP2; 137 amino acid residues) is supposed to play an important role in initiation of chromatin condensation and cessation of transcriptional activity during mammalian spermiogenesis. Boar TP2 has three potential zinc finger motifs and binds three atoms of zinc per molecule. However the structure of the zinc‐binding domain of boar TP2 has not been completely determined. To elucidate the local structure around the zinc atoms of boar TP2, we performed an X‐ray absorption fine structure (XAFS) measurement on the zinc‐binding domain of TP2(TP2Z)(residues 1‐103) in the fluorescence mode. By EXAFS analyses we have demonstrated that each of the three zinc atoms is coordinated by approximately two sulfur and two nitrogen atoms on average. The average Zn‐S and Zn‐N distances were found to be 2.36 Å and 2.01 Å, respectively. The sulfur and nitrogen atoms are attributed to cysteine and histidine residues, respectively, from comparison of the EXAFS spectra with model compounds ZnS and ZnTPP(zinc(II) tetraphenylporphyrin).