1
|
Roeters SJ, Golbek TW, Bregnhøj M, Drace T, Alamdari S, Roseboom W, Kramer G, Šantl-Temkiv T, Finster K, Pfaendtner J, Woutersen S, Boesen T, Weidner T. Ice-nucleating proteins are activated by low temperatures to control the structure of interfacial water. Nat Commun 2021; 12:1183. [PMID: 33608518 PMCID: PMC7895962 DOI: 10.1038/s41467-021-21349-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 01/22/2021] [Indexed: 11/17/2022] Open
Abstract
Ice-nucleation active (INA) bacteria can promote the growth of ice more effectively than any other known material. Using specialized ice-nucleating proteins (INPs), they obtain nutrients from plants by inducing frost damage and, when airborne in the atmosphere, they drive ice nucleation within clouds, which may affect global precipitation patterns. Despite their evident environmental importance, the molecular mechanisms behind INP-induced freezing have remained largely elusive. We investigate the structural basis for the interactions between water and the ice-nucleating protein InaZ from the INA bacterium Pseudomonas syringae. Using vibrational sum-frequency generation (SFG) and two-dimensional infrared spectroscopy, we demonstrate that the ice-active repeats of InaZ adopt a β-helical structure in solution and at water surfaces. In this configuration, interaction between INPs and water molecules imposes structural ordering on the adjacent water network. The observed order of water increases as the interface is cooled to temperatures close to the melting point of water. Experimental SFG data combined with molecular-dynamics simulations and spectral calculations show that InaZ reorients at lower temperatures. This reorientation can enhance water interactions, and thereby the effectiveness of ice nucleation. Ice-nucleating proteins promote ice formation at high sub-zero temperatures, but the mechanism is still unclear. The authors investigate a model ice-nucleating protein at the air-water interface using vibrational sum frequency generation spectroscopy and simulations, revealing its reorientation at low temperatures, which increases contact with water molecules and promotes their ordering.
Collapse
Affiliation(s)
- Steven J Roeters
- Department of Chemistry, Aarhus University, Aarhus C, Denmark.,Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | | | - Mikkel Bregnhøj
- Department of Chemistry, Aarhus University, Aarhus C, Denmark
| | - Taner Drace
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark
| | - Sarah Alamdari
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
| | - Winfried Roseboom
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Gertjan Kramer
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Tina Šantl-Temkiv
- Department of Biology, Aarhus University, Aarhus C, Denmark.,The Stellar Astrophysics Centre - SAC, Department of Physics and Astronomy, Aarhus University, Aarhus C, Denmark
| | - Kai Finster
- Department of Biology, Aarhus University, Aarhus C, Denmark.,The Stellar Astrophysics Centre - SAC, Department of Physics and Astronomy, Aarhus University, Aarhus C, Denmark
| | - Jim Pfaendtner
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
| | - Sander Woutersen
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Thomas Boesen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C, Denmark.,Interdisciplinary Nanoscience Center - iNano, Aarhus University, Aarhus C, Denmark
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, Aarhus C, Denmark. .,Department of Chemical Engineering, University of Washington, Seattle, WA, USA. .,Interdisciplinary Nanoscience Center - iNano, Aarhus University, Aarhus C, Denmark.
| |
Collapse
|
2
|
Lee Y, Kwak C, Jeong KW, Durai P, Ryu KS, Kim EH, Cheong C, Ahn HC, Kim HJ, Kim Y. Tyr51: Key Determinant of the Low Thermostability of the Colwellia psychrerythraea Cold-Shock Protein. Biochemistry 2018; 57:3625-3640. [PMID: 29737840 DOI: 10.1021/acs.biochem.8b00144] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cold-shock proteins (Csps) are expressed at lower-than-optimum temperatures, and they function as RNA chaperones; however, no structural studies on psychrophilic Csps have been reported. Here, we aimed to investigate the structure and dynamics of the Csp of psychrophile Colwellia psychrerythraea 34H, ( Cp-Csp). Although Cp-Csp shares sequence homology, common folding patterns, and motifs, including a five β-stranded barrel, with its thermophilic counterparts, its thermostability (37 °C) was markedly lower than those of other Csps. Cp-Csp binds heptathymidine with an affinity of 10-7 M, thereby increasing its thermostability to 50 °C. Nuclear magnetic resonance spectroscopic analysis of the Cp-Csp structure and backbone dynamics revealed a flexible structure with only one salt bridge and 10 residues in the hydrophobic cavity. Notably, Cp-Csp contains Tyr51 instead of the conserved Phe in the hydrophobic core, and its phenolic hydroxyl group projects toward the surface. The Y51F mutation increased the stability of hydrophobic packing and may have allowed for the formation of a K3-E21 salt bridge, thereby increasing its thermostability to 43 °C. Cp-Csp exhibited conformational exchanges in its ribonucleoprotein motifs 1 and 2 (754 and 642 s-1), and heptathymidine binding markedly decreased these motions. Cp-Csp lacks salt bridges and has longer flexible loops and a less compact hydrophobic cavity resulting from Tyr51 compared to mesophilic and thermophilic Csps. These might explain the low thermostability of Cp-Csp. The conformational flexibility of Cp-Csp facilitates its accommodation of nucleic acids at low temperatures in polar oceans and its function as an RNA chaperone for cold adaptation.
Collapse
Affiliation(s)
- Yeongjoon Lee
- Department of Bioscience and Biotechnology , Konkuk University , Seoul 05029 , Republic of Korea
| | - Chulhee Kwak
- Department of Bioscience and Biotechnology , Konkuk University , Seoul 05029 , Republic of Korea
| | - Ki-Woong Jeong
- Department of Bioscience and Biotechnology , Konkuk University , Seoul 05029 , Republic of Korea
| | - Prasannavenkatesh Durai
- Department of Bioscience and Biotechnology , Konkuk University , Seoul 05029 , Republic of Korea
| | - Kyoung-Seok Ryu
- Division of Magnetic Resonance , KBSI , Chungbuk 28119 , Republic of Korea
| | - Eun-Hee Kim
- Division of Magnetic Resonance , KBSI , Chungbuk 28119 , Republic of Korea
| | - Chaejoon Cheong
- Division of Magnetic Resonance , KBSI , Chungbuk 28119 , Republic of Korea
| | - Hee-Chul Ahn
- College of Pharmacy , Dongguk University , Goyang , Gyeonggi-do 410-820 , Republic of Korea
| | - Hak Jun Kim
- Department of Chemistry , Pukyong National University , Busan 48547 , Republic of Korea
| | - Yangmee Kim
- Department of Bioscience and Biotechnology , Konkuk University , Seoul 05029 , Republic of Korea
| |
Collapse
|