TY - JOUR
T1 - Histidine 332 of the D1 polypeptide modulates the magnetic and redox properties of the manganese cluster and tyrosine Y(z) in photosystem II
AU - Debus, Richard J.
AU - Campbell, Kristy A.
AU - Peloquin, Jeffrey M.
AU - Pham, Donna P.
AU - Britt, R. David
PY - 2000/1/18
Y1 - 2000/1/18
N2 - An electron spin-echo envelope modulation study [Tang, X.-S., Diner, B. A., Larsen, B. S., Gilchrist, M. L., Jr., Lorigan, G. A., and Britt, R. D. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 704-708] and a recent Fourier transform infrared study [Noguchi, T., Inoue, Y., and Tang, X.-S. (1999) Biochemistry 38, 10187-10195], both conducted with [15N]histidine-labeled photosystem II particles, show that at least one histidine residue coordinates the O2-evolving Mn cluster in photosystem II. Evidence obtained from site-directed mutagenesis studies suggests that one of these residues may be His332 of the D1 polypeptide. The mutation D1-H332E is of particular interest because cells of the cyanobacterium Synechocystis sp. PCC 6803 that contain this mutation evolve no O2 but appear to assemble Mn clusters in nearly all photosystem II reaction centers [Chu, H.-A., Nguyen, A. P., and Debus, R. J. (1995) Biochemistry 34. 5859-5882]. Photosystem II particles isolated from the Synechocystis D1-H332E mutant are characterized in this study. Intact D1-H332E photosystem II particles exhibit an altered S2 state multiline EPR signal that has more hyperfine lines and narrower splittings than the S2 state multiline EPR signal observed in wild-type* PSII particles. However, the quantum yield for oxidizing the S1 state Mn cluster is very low, corresponding to an 8000-fold slowing of the rate of Mn oxidation by Y(z)·, and the temperature threshold for forming the S2 state is approximately 100 K higher than in wild-type PSII preparations. Furthermore, the D1-H332E PSII particles are unable to advance beyond the Y(z)·S2 state, as shown by the accumulation of a narrow 'split' EPR signal under multiple turnover conditions. In Mn-depleted photosystem II particles, charge recombination between Q(A)·- and Y(z)· in D1-H332E is accelerated in comparison to wild-type*, showing that the mutation alters the redox properties of Y(z) in addition to those of the Mn cluster. These results are consistent with D1-His332 being located near the Mn-Y(z) complex and perhaps ligating Mn.
AB - An electron spin-echo envelope modulation study [Tang, X.-S., Diner, B. A., Larsen, B. S., Gilchrist, M. L., Jr., Lorigan, G. A., and Britt, R. D. (1994) Proc. Natl. Acad. Sci. U.S.A. 91, 704-708] and a recent Fourier transform infrared study [Noguchi, T., Inoue, Y., and Tang, X.-S. (1999) Biochemistry 38, 10187-10195], both conducted with [15N]histidine-labeled photosystem II particles, show that at least one histidine residue coordinates the O2-evolving Mn cluster in photosystem II. Evidence obtained from site-directed mutagenesis studies suggests that one of these residues may be His332 of the D1 polypeptide. The mutation D1-H332E is of particular interest because cells of the cyanobacterium Synechocystis sp. PCC 6803 that contain this mutation evolve no O2 but appear to assemble Mn clusters in nearly all photosystem II reaction centers [Chu, H.-A., Nguyen, A. P., and Debus, R. J. (1995) Biochemistry 34. 5859-5882]. Photosystem II particles isolated from the Synechocystis D1-H332E mutant are characterized in this study. Intact D1-H332E photosystem II particles exhibit an altered S2 state multiline EPR signal that has more hyperfine lines and narrower splittings than the S2 state multiline EPR signal observed in wild-type* PSII particles. However, the quantum yield for oxidizing the S1 state Mn cluster is very low, corresponding to an 8000-fold slowing of the rate of Mn oxidation by Y(z)·, and the temperature threshold for forming the S2 state is approximately 100 K higher than in wild-type PSII preparations. Furthermore, the D1-H332E PSII particles are unable to advance beyond the Y(z)·S2 state, as shown by the accumulation of a narrow 'split' EPR signal under multiple turnover conditions. In Mn-depleted photosystem II particles, charge recombination between Q(A)·- and Y(z)· in D1-H332E is accelerated in comparison to wild-type*, showing that the mutation alters the redox properties of Y(z) in addition to those of the Mn cluster. These results are consistent with D1-His332 being located near the Mn-Y(z) complex and perhaps ligating Mn.
UR - https://www.scopus.com/pages/publications/0034681146
U2 - 10.1021/bi9917737
DO - 10.1021/bi9917737
M3 - Article
C2 - 10631009
AN - SCOPUS:0034681146
SN - 0006-2960
VL - 39
SP - 470
EP - 478
JO - Biochemistry
JF - Biochemistry
IS - 2
ER -