It was awarded for his "outstanding achievements in molecular biology and molecular neuroscience".
Prof Tate was somewhat stunned to receive the country's highest science award.
It had been gained by only one other Otago University researcher, Prof Tate's PhD supervisor in the biochemistry department, Prof George Petersen, himself long a pioneer in DNA research.
"As the ultimate [science] award in New Zealand, it's unbelievable," he said.
As the medal-winner, Prof Tate also receives $100,000 from the Government.
His award, announced at an annual research honours ceremony in Christchurch, hosted by the Royal Society, came as part of a stellar day for Dunedin researchers.
At the ceremony yesterday, Dunedin scientists received a record eight awards.
Seven of those were for researchers based at Otago University, including Prof Frank Griffin, who heads the microbiology and immunology department.
He gained the Royal Society of New Zealand's Pickering Medal, the country's top award for achievement in technology - the first time this has been won by an Otago University researcher.
Prof Richie Poulton, director of the university's Dunedin Multidisciplinary Health and Development Research Unit, was also one of two winners of the Dame Joan Metge Award for Social Sciences.
Prof Tate, who has been working in the biochemistry department since the 1970s, was quick to pay tribute to Prof Petersen, who had had an "incredible influence" on him.
Prof Tate said Otago University had been "incredibly supportive" over the years and he also praised Dunedin as a city of creative people, in music, drama and the other arts as well as in science.
"Dunedin has a wonderful ambience for my sort of creative activity."
He has long enjoyed singing in the City of Dunedin Choir and a highlight came when he sang the South African national anthem at Carisbrook before a test match between the All Blacks and Springboks two years ago.
Prof Tate, who is involved in cutting-edge research into HIV and neurological diseases such as Alzheimer's, said he had made some "significant discoveries" over the years, but worked away quietly at his research, day by day.
"I don't get up each morning thinking great thoughts, to make the spectacular discovery today," he said with a smile. Other national awards went to Dr David Galloway, of Landcare Research Dunedin, Hutton Medal for "excellence in plant science"; Prof Stephen Robertson, Liley Medal, Health Research Council, for "an outstanding contribution" to health and medical sciences; Prof Keith Gordon, New Zealand Institute of Chemistry Maurice Wilkins Centre Prize for Chemical Science; Dr John Reynolds, of anatomy and structural biology; and physicist Dr Ashton Bradley, Rutherford Discovery Fellowships to support research, providing up to $200,000 a year for five years.
