A research team from Chiba Institute of Technology and others discovered that combining RNA and DNA in nucleic acid aptamers alters their flexibility and adjusts how they fit target proteins. The study revealed that an RNA-DNA chimeric aptamer exhibits larger structural fluctuations than a pure RNA aptamer, allowing it to adapt its shape and bind more extensively to the target protein's surface. This induced-fit molecular recognition will contribute to designing next-generation aptamer therapeutics and sensors.