1OTI

E46Q MUTANT OF PHOTOACTIVE YELLOW PROTEIN, P65 AT 295K

Summary for 1OTI

• Entry DOI: 10.2210/pdb1oti/pdb
• Related: 1OTA 1OTB 1OTD 1OTE 2PHY
• Descriptor: Photoactive yellow protein, 4'-HYDROXYCINNAMIC ACID (3 entities in total)
• Functional Keywords: pyp, signaling protein
• Biological source: Halorhodospira halophila
• Total number of polymer chains: 1
• Total formula weight: 14051.75

Authors

Anderson, S.,Crosson, S.,Moffat, K. (deposition date: 2003-03-21, release date: 2004-05-11, Last modification date: 2023-08-16)

Primary citation

Anderson, S.,Crosson, S.,Moffat, K.
Short hydrogen bonds in photoactive yellow protein.
Acta Crystallogr.,Sect.D, 60:1008-1016, 2004

PubMed Abstract: Eight high-resolution crystal structures of the ground state of photoactive yellow protein (PYP) solved under a variety of conditions reveal that its chromophore is stabilized by two unusually short hydrogen bonds. Both Tyr42 Oeta and Glu46 Oepsilon are separated from the chromophore phenolate oxygen by less than the sum of their atomic van der Waals radii, 2.6 angstroms. This is characteristic of strong hydrogen bonding, in which hydrogen bonds acquire significant covalent character. The hydrogen bond from the protonated Glu46 to the negatively charged phenolate oxygen is 2.58 +/- 0.01 angstroms in length, while that from Tyr42 is considerably shorter, 2.49 +/- 0.01 angstroms. The E46Q mutant was solved to 0.95 angstroms resolution; the isosteric mutation increased the length of the hydrogen bond from Glx46 to the chromophore by 0.29 +/- 0.01 angstroms to that of an average hydrogen bond, 2.88 +/- 0.01 angstroms. The very short hydrogen bond from Tyr42 explains why mutating this residue has such a severe effect on the ground-state structure and PYP photocycle. The effect of isosteric mutations on the photocycle can be largely explained by the alterations to the length and strength of these hydrogen bonds.

PubMed: 15159559
DOI: 10.1107/S090744490400616X

Experimental method

X-RAY DIFFRACTION (1.4 Å)